Building Material Use and Associated Environmental Impacts in China

Subscriber access provided by Kaohsiung Medical University

Energy and the Environment

Building material use and associated environmental impacts in China 2000-2015 beijia huang, feng zhao, Tomer Fishman, Wei-Qiang Chen, Niko Heeren, and Edgar G. Hertwich Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.8b04104 • Publication Date (Web): 09 Nov 2018 Downloaded from http://pubs.acs.org on November 10, 2018

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 26

Environmental Science & Technology

1

Building material use and associated environmental impacts in

2

China 2000-2015

3 4 5 6 7 8 9 10 11 12

Beijia Huanga, b*, Feng Zhao a, Tomer Fishmanb,c, Wei-Qiang Chend,e,f, Niko Heerenb, Edgar G. Hertwichb

13

Abstract: A rapidly increasing use of building materials poses threats to resources and

14

the environment. Using novel, localized life cycle inventories and building material

15

intensity data, this study quantifies the resource use of building materials in mainland

16

China and evaluates their embodied environmental impacts. Newly built floor area and

17

related material consumption grew 11% per annum from 2000 to 2015, leveling off at the

18

end of this period. Concrete, sand, gravel, brick, and cement were the main materials

19

used. Spatially, construction activities expanded from east China into the central part of

20

the country. Cement, steel, and concrete production are the key contributors to associated

21

environmental impacts, e.g. cement and steel each account for around 25% of the global

22

warming potential from building materials. Building materials contribute considerably to

23

the impact categories of human toxicity, fossil depletion, and global warming,

24

emphasizing that greenhouse gas emissions should not be the sole focus of research on

25

environmental impacts of building materials. These findings quantitatively shed light on

26

the urgent need to reduce environmental impacts and to conserve energy in the

27

manufacturing processes of building materials on the national scale.

a

College of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, China

b Center

for Industrial Ecology, School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA c

d

IDC Herzliya School of Sustainability, Herzliya, Israel

Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Science, Xiamen, China e f

Xiamen Key Lab of Urban Metabolism, Xiamen, China

University of Chinese Academy of Science, Beijing, China

1

ACS Paragon Plus Environment


28 29 30 31

Key words: building materials; environmental impacts; China; life cycle assessment; material flow accounting; construction

32

2


Page 2 of 26

Page 3 of 26

33


INTRODUCTION

34

Globally, building materials represent the largest material flows entering urban areas

35

after water, and the largest waste category1. Around half of all materials extracted from

36

the earth’s crust annually are transformed into building materials and products2,3. The

37

extensive use of building materials has important impacts on resource consumption and

38

the environment4. Environmental problems associated with the building material

39

consumption extend from the local scale (e.g., terrestrial ecotoxicity) to the global scale

40

(e.g., Climate Change)5. China's rapid economic and social development has been

41

associated with an unprecedented boom of buildings construction6,7. Annual construction

42

in China accounts for almost half of the world's building construction8 and has caused

43

substantial resource demands and serious pollution. The study of embodied

44

environmental impacts9 of building materials in China is important for a deeper

45

understanding of how buildings cause environmental impacts. It can offer a basis for

46

establishing environmental policies and control strategies in the building sector such as

47

green building material certifications.

48

A fair number of studies investigated building material flows and stocks on the

49

national scale. Examples include Kapur et al.10, Fishman et al.11,12, Tanikawa et al.13,

50

Heeren and Hellweg14, and Sandberg et al.15,16 who estimated building material stocks in

51

countries such as Japan, the United States, Switzerland, and Norway with various

52

methods. There has also been a growing interest in the rapid urbanization of China. For

53

instance, Hu et al.17 modeled the evolution of steel demand for buildings in China, and

54

Cao et al.18 estimated Chinese in-use cement stocks and relevant flow characteristics. 3



55

Hong et al. 19forecasted that building areas and material stocks in China would reach their

56

peak around 2028. The models of Huang et al.8 and Cai et al.20 demonstrated that

57

prolonging Chinese building lifetimes and strengthening the recycling of materials are

58

two key measures for reducing raw material demand and associated emissions.

59

Focusing on the environmental impacts of buildings materials, multiple studies5,21-24

60

quantified energy consumption during the building production process and assessed

61

corresponding GHG emissions. Other studies2531 estimated cradle-to-gate emissions of

62

nitrogen oxides (NOx), sulfur oxides (SOx), and other pollutants associated with building

63

materials, although some were limited to specific materials including concrete, steel, and

64

cement. Comparative analyses of various environmental impacts of different building

65

materials were conducted32-34 to identify environmentally friendly materials. Thormark33,

66

Bribián et al.34 and Heeren et al.35 found that the choice of materials such as wood and

67

recycled materials can considerably reduce the associated environmental impacts of

68

building materials.

69

Previous research focused mainly on the energy consumption and greenhouse gas

70

emissions, including trade-offs between building material production and building

71

operation. There has been less focus on other environmental impacts such as toxicity,

72

resource depletion, and eutrophication caused by building material production. Especially

73

for China, most studies were limited to individual materials such as steel or cement.

74

Moreover, comprehensive estimation of Chinese building material use trends covering

75

both the spatial and temporal dimensions is still scant.

4


Page 4 of 26

Page 5 of 26


76

To fill these research gaps, this study investigates: (1) What kinds, how much, and

77

in which building types have building materials been used in recent years in China, and

78

what are their development trends? (2) What are the primary environmental impacts

79

caused by producing these building materials? (3) What is the spatial distribution of the

80

key embodied environmental impacts? In addition to the nation-wide time series of 16

81

years, we also explore the variation of material use and associated environmental impact

82

across different provinces of Mainland China.

83

METHODS

84

Research procedures

85

The research was conducted in three steps as illustrated in Figure.1: (1) Classify buildings

86

and building materials into types; (2) Calculate the annual building material use from

87

2000 to 2015; and (3) Estimate environmental impacts associated with building materials

88

production.

89

5



90

Page 6 of 26

Building Material

91 92

Building types

Step 1

Residential Buildings

Plant & Warehouse

Office

Commercial

Education & culture

Healthcare & Medicine

Research

Other Buildings

Key material categories

93

Steel

Cement

Concrete

Wood

Brick

Sand

Gravel

lime

Glass

Ceramic tile

94 Step 2

95 96 Step 3

97

Annual constructed floor area for each type of building

Building intensity coefficients for each type of building

Input-output production inventory for each material

Spatial and time series data of material use

LCA assessment & Spatial disparity analysis

98

Materials used

Environmental Impact burden for each material

Environmental Impact for annual used material

Figure.1 Research steps

99

In step one, building types were classified as residential and seven types of non-

100

residential buildings (Office, Education and cultural, Research, Plant and warehouse,

101

Commercial, Healthcare and medicine, and other buildings) in accordance with the

102

Chinese statistical yearbooks36. The key building material categories were identified to

103

be steel, concrete, cement (for non-concrete uses, for instance plaster and mortar), wood,

104

brick, sand (non-concrete use), gravel (non-concrete use), limestone, glass, and ceramic

105

tiles, as indicated by Hong37, Huang38and Chang6. We note that some materials not

106

investigated in this research, such as aluminum, may also cause non-negligible influence

107

on the environment due to their embodied energy and impacts and should be a focus of

108

future studies.

109

In step two, the annual building material use from 2000 to 2015 was calculated by

110

multiplying annual constructed floor areas for each type of buildings in each province by

111

building material composition intensity coefficients: 6


Page 7 of 26


𝑡,𝑘 𝑀𝑈𝑡,𝑘 𝑖 = ∑𝑗(𝐵𝑖,𝑗 × 𝑀𝐼𝑖,𝑗)

112

𝑀𝑈𝑡𝑖 = ∑𝑘𝑀𝑈𝑡,𝑘 𝑖

113

MU

114

t,k i

(1a) (1b)

is the use (which can also be termed the consumption, inflow, or the gross

115

addition to the stock of buildings) of material i in province k in year t in kg, summed for

116

the eight building types j; 𝑀𝑈𝑡𝑖 is the annual material use for all provinces of China; B

117

t,k j is

118

MI

119

of building material i per floor area (m2) of building type j (kg/m2).

the total newly constructed floor area of building type j in province k in year t; and

i,j is

the building material composition intensity coefficient, the average ratio of mass

120

Data of the annually constructed floor area (B) for each type of building were

121

collected from the National Statistical Yearbooks on Construction (NBS, 2001-2016)38

122

and Construction Industry Statistical Yearbooks (CSYC, 2001-2016)39. The building

123

material composition intensity coefficients for each building type are derived from

124

Chang5 and Zhao et al.40, in which MI values were collected and estimated in a bottom-

125

up way, including building evaluation manuals, assets evaluation data and parameters

126

manuals and onsite investigations. We took the average value when residential buildings

127

were classified in different groups. Volume data was converted into mass by density for

128

specific materials. These data sources have not clearly indicated any changes to building

129

material intensities within our research period or among provinces, and so we assume

130

them to be spatially and temporally uniform (Figure.2). Further building material

131

intensity data is detailed in the supporting information Table S1.

132

7



133

3500

Ceramic tiles

137

Material Intensity(Kg/m2)

136

Glass

Lime

Gravel

Sand

Brick

Wood

Concrete

Cement(non-concrete use)

Steel

3000

134 135

Page 8 of 26

2500

2000

1500

1000

500

138 0

139 140

Residential

Plant and warehouse

Office

Commercial Education and Healthcare and culture medicine

Research

Other buildings

Figure.2 Materials use intensities (kg/m2) for the eight building types in China, 2015

141

In step three, the embodied environmental impacts associated with the annual building

142

material use ( MU

143

inventories for most of the materials are from the Sinocenter database 201443, while

144

concrete (CN, C30/70) and cement (CN, average) are from Gabi 6 because the Sinocenter

145

data not yet included these two materials. Environmental impacts per kg of building

146

material (Ek) are evaluated by applying the mid-point parameters of the ReCiPe 2016 H

147

method, which is a commonly used life cycle impact assessment method with up-to-date

148

environmental impact indicators and normalization values41. Moreover, the ReCiPe

149

method covers China with its global scope impact mechanism.

t,k i ),

were estimated using life cycle assessment. The life cycle

150

Besides the evaluation of environmental impact per kg of building material (Ek), we

151

also analyze environmental impact considering the annual material use amount (Ev). This

152

is important because materials are used in different amounts for specific buildings, and it

153

is quite possible that materials with higher per-mass environmental burden are consumed

8


Page 9 of 26

154


at lower rates and vice-versa. Ev was calculated according to equation (2). 𝐸𝑣𝑡𝑖,𝑥 = 𝑀𝑈𝑡𝑖 × 𝐸𝑘𝑖,𝑥

155

(2)

156

𝐸𝑣𝑡𝑖,𝑥 is the total magnitude of environmental impact x for material i in year t from

157

all construction, summed for the eight building types j; 𝐸𝑘𝑖,𝑗,𝑥 is the per-kg Environmental

158

impact x of material i in building type j; and 𝑀𝑈𝑡,𝑘 is the annual use of material i of year t in 𝑖

159

province k.

160

We carried out environmental impact characterization and normalization on the mid-

161

point level42,43 to compare the contribution of building materials to the total global

162

impacts in different impact categories. In normalization, the characterized results of each

163

impact category are divided by a selected reference value (R) which brings all the results

164

to the same scale (equation 3). Such normalization facilitates the interpretation of the

165

results and helps us link the relative contributions of each building material to each type

166

of environmental impact. The normalization factors in our study refer to version 1.08 of

167

LCA ReCiPe midpoint normalization world level 200044, and the reference value in our

168

study is set as China’s population in 2000 (1.27 billion)38 multiplied by the per capita

169

world level impact in ReCiPe. 𝑁𝑣𝑡𝑖,𝑥

170

=

𝐸𝑣𝑡𝑖,𝑥 𝑅𝑥

（3）

171

𝑁𝑣𝑡𝑖,𝑥 is the normalization result of environmental impact x for the Total magnitude

172

of environmental impact x for material i in year t from all construction, R(x) is the

173

reference factor for environmental impact category x; 𝐸𝑣𝑡𝑖,𝑥 is the total magnitude of

174

environmental impact x for material i in year t from all construction, summed for the eight

175

building types j. 9



176

Past studies have shown that different life cycle impact assessment methods may

177

provide different results when analyzing impacts from building materials47, and so we

178

also use the CML 200145 method to compare and discuss our key findings, noting that

179

most other LCA approaches are not fit for the case of China. The normalization factors

180

of CML2001 (version Jan 2016, World level 2000) are used in this study.

181

System boundaries

182

The system boundary of this study is the production phase of building materials (cradle-

183

to-gate), which means the associated environmental impact we evaluated include raw

184

material extraction, processing and manufacturing. Our data and methods enable to

185

estimate the “embodied” environmental impact, without detecting where the materials are

186

produced, i.e., where the environmental pollutions are emitted. The research period is

187

2000 to 2015, because China began to account annual construction floor area by building

188

types from 2000 onward.

189 190

RESULTS

191

Building materials use

192

Growth of new building area in China (2000-2015)

193

From 2000 to 2015, China's construction industry experienced rapid development and the

194

average annual growth rate of new construction area was 11% in this period. The

195

construction area of residential buildings has been expanding much more rapidly than the

196

non-residential building types (Figure. 3). In 2015, the newly-added construction area of 10


Page 10 of 26

Page 11 of 26


residential buildings was about twice that of non-residential buildings. The newly

198

constructed building area levelled off in 2015, perhaps due to the growing control of real

199

estate development from both central and local governments46. A research report from

200

ZhongShan Realty Research Center indicated that the supply of construction land from

201

the government has been declining since 201347.

New constructed building areas （Billion m2）

197

4.5

Other buildings

Research

4.0

Healthcare and medicine

Education and cultural

3.5

Commercial

Office

3.0

Plant and warehouse

Residential

2.5 2.0 1.5 1.0 0.5 0.0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

202 203 204

Figure.3 Annual gross new constructed building floor area in China (2000-2015)

205

Trends in building materials use (2000-2015)

206

In the year 2000 China used 2 billion tons of building materials, a number that increased

207

to 10 billion tons by 2014 before leveling off (Figure. 4). The most used building materials

208

by mass were concrete, sand and gravel, followed by bricks and cement for non-concrete

209

applications. Steel, limestone, and wood were used in relatively lower quantities.

210 211 212 213

11


216 217 218 219

12.0

30

10.0

25

8.0

20

6.0

15

4.0

10

2.0

5

Concrete

0.0

0

Cement(nonconcrete use) Steel

Glass Lime Gravel Sand Brick Wood

2000

220

Ceramic tile

2002

2004

-2.0

2006

2008

2010

2012

2014

-5

Year

Annual Growth Rate (%)

215

Material Use (Billion t)

214

Page 12 of 26

Annual


Growth Rate

221 222

Figure.4 Annual use of building materials for newly constructed buildings, 2000-2015 (bar plot, left-hand

223

Environmental impacts

224

In the Chinese case, steel, lime, glass, wood, and cement were found to have

225

comparatively higher environmental impacts per kg (Ek) than the other materials, using

226

ReCiPe. A comparison with the CML indicator results indicates a consistent order of the

227

environmental burden ranking. Detailed characterized midpoint environmental impacts

228

per kg of building material with both methods are provided in the Supporting Information

229

Table S3, Table S4.

axis) and annual growth rate of building material use (line plot, right-hand axis)

230

Scaling up the ReCiPe environmental impacts from 1 kg to annual use amounts

231

(Ev), we aggregate the contribution of each material to every impact category. The

232

assessment results are illustrated in Figure.5 using 2015 as an exemplary case (the 13

233

highest of the 18 environmental indicators are presented; Absolute characterized

234

environmental impacts and normalized results using ReCiPe can be found in Supporting

235

Information Table S5, Table S6). Overall, building materials contribute most significantly 12


Page 13 of 26


236

to the environmental indicators of human toxicity, fossil fuel depletion, global warming,

237

and metal depletion based on midpoint characterization and normalization.

238

In general, four materials – cement, steel, concrete, and brick – are the key

239

contributors to the environmental impacts of building materials. The contributions of

240

some materials are due to their high use (e.g. concrete, sand, gravel, and brick). Other

241

materials have disproportionate contribution to various impacts despite their

242

comparatively low use by mass (cf. Figure 4). Steel is the most prominent example, but

243

also lime, glass, and wood. Cement stands out as a material whose high contribution to

244

impacts is a combination of both high usage and high impacts per kg. Steel

Particulate matter formation

Cement(non-concrete use)

Ionising radiation

Concrete Wood

Metal depletion

Brick

Photochemical oxidant formation

Sand

Terrestrial ecotoxicity

Gravel Lime

Freshwater ecotoxicity

Glass

Marine ecotoxicity

Ceramic tiles

Human toxicity Marine eutrophication Freshwater eutrophication Fossil depletion Terrestrial acidification Climate change 0.00

0.10

0.20

0.30

0.40

0.50

245 246 247

Figure.5 Environmental impact indicators associated with the production of building material used in 2015, using the ReCiPe method, normalized to global indicators in 2000 (Nv, cf. equation 2)

248

Tracing the sources of these key environmental indicators, human toxicity is 48)

249

primarily caused by the heavy metals (including arsenic, cadmium, zinc, lead, etc.

250

emitted in the mining and manufacturing processes of cement, concrete, and bricks. Fossil 13



251

depletion is mainly caused by the large demand of coal, petroleum, electricity, and natural

252

gas in the manufacturing process of steel, brick, gravel, and cement. The largest

253

contributions to global warming come from steel and cement production and each account

254

for around 25% of total impact from building materials (Figure. 6). Global warming

255

burdens originate in the large energy consumption during the production processes of

256

steel, cement, and concrete49,50,51 and in the chemical reactions of clinker production for

257

cement manufacture55. Ceramic tiles 1% Glass 0% Lime, 13% Steel, 25% Gravel, 8% Sand, 0.4% Brick, 12% Wood, 3%

Cement(nonconcrete use), 24% Concrete, 14%

258 259

Figure. 6 Share of global warming impacts from building material use in China in 2015

260

Characterization and normalization using the alternative CML method (Supporting

261

Information Table S7, Table S8) consistently indicate that global warming, human

262

toxicity, and fossil depletion are the top impacts.

263

Spatial disparities

264

The spatial distributions of annual new constructed floor area in 2000 and 2015 are

265

compared in Figure.7. In 2000, construction activities primarily occurred in China's

266

eastern region, especially in Jiangsu (JS) and Zhejiang (ZJ) provinces. Since then

14


Page 14 of 26

Page 15 of 26


267

construction has expanded westward to central China, including provinces such as

268

Sichuan (SC), Hebei (HB), and Henan (HN). We noticed that province with the largest

269

population-- Guangdong experienced slower construction in this period compared with

270

the eastern and central provinces. This corresponds with a local statistic report52

271

revealing that Guangdong now has lower per-capita living space than Zhejiang and

272

Jiangsu. Residential buildings are the main construction types in all provinces, but there

273

appear to be regional variances in the proportions of other building types. As revealed in

274

Figure.7 (b), non-residential buildings in Shanghai (SH), Beijing (BJ), and Zhejiang (ZJ)

275

provinces have relatively higher proportion compared to other provinces.

276 (a) 2000

(b) 2015

BJ

BJ HB

HN SC

HB

HN

JS SH

SC

ZJ

1,000 m2/y

JS SH ZJ

Mt CO2 eq. /y

10,000 m2/y Others Research

277

Residential Plant and

75,000 warehouse m2/y Office

Healthcare and medicine Education and culture

Commercial

278

Figure.7 The spatial distribution of the annual constructed floor area and associated GHG emission in

279

China in (a) 2000 and (b) 2015

280

Figure.7 also indicates the spatial disparity of GHG emissions associated with

281

building material use in 2000 and 2015 (grey color scale). Nation-wide embodied GHG

282

emissions associated with building materials increased sharply from 490 million tons (Mt) 15



283

CO2eq in 2000 to 2.4Gt CO2eq per year in 2015. The embodied GHG emissions of

284

building materials in 2015 accounts for 24% of China’s total GHG emissions (10Gt53).

285

Similar to the spatial distribution of annual constructed floor area, GHG emissions in

286

2000 were the highest in eastern China, while a rising trend has begun to emerge in the

287

central part of China in recent years.

288

The spatial distributions of other environmental impacts beyond GHG are

289

exemplified by human toxicity and fossil depletion in the Supplement Information Figure

290

S3 and Figure S4. The spatial distributions of the three environmental impacts are similar

291

because the leading environmental impacts are closely correlated with the use of concrete,

292

cement, and steel.

293

DISCUSSION

294

China’s development trends

295

Our findings quantify the notion that the construction boom during 2000-2015

296

contributed significantly to the rapid growth in pollution and resource depletion in China.

297

China's construction industry experienced rapid development. Annually constructed floor

298

area rate increased around five-fold in the period of 2000 to 2015. Studies of the trajectory

299

of building material consumption of other countries have shown that the rate of new

300

construction of dwellings declines after a period of rapid growth, for example since 1970

301

in Norway54 and 1995 in the Netherlands55. In Japan’s case, material accumulation

302

increased rapidly in the 1960s, peaked in 2005-2008, and has decreased slightly since

303

then56. Our results show that in China inflow was static in 2014-2015. Other research

304

suggests that the annual demand for building materials began to decrease already around 16


Page 16 of 26

Page 17 of 26


305

201039. One scenario indicates that the building material stock may reach its peak in 20307.

306

It remains to be seen whether the 2014-2015 trend indicates a long-term stabilization of

307

annual construction rates, an inflection point that may ultimately lead to a stabilization of

308

the building stock, or simply an outlier.

309

The spatial disparity analysis reveals regional differences in building material use

310

and embodied impacts, according to the building types constructed. Our results display

311

the expansion of construction activities from China's eastern region in 2000 into the

312

central parts of the country in recent years. This migration of new construction activities

313

indicates a need to strengthen building material regulations in provinces such as Jiangsu,

314

Zhejiang, Sichuan and Henan. At the same time, focus should be given to the building

315

types consuming the largest amount of building materials-- residential buildings, plants

316

and warehouses, as revealed in our study (see Supporting Information Table S9). Policy

317

strategies such as green building materials certification programs should be given

318

attention and reinforced to promote the cleaner production for building materials, since

319

now the program covers only concrete, glass and ceramic tile, and is in its beginning stage

320

of implementation in China57. Extended producer responsibility may also be an option for

321

the high recycling potential materials such as concrete, steel and wood58. Holding

322

building material producers responsible for managing certain building waste encourages

323

manufacturers to design more environmentally friendly and recyclable materials.

324

Contribution of Environmental impacts

325

Past studies often analyzed the impacts of individual building materials or the magnitudes

326

of consumption, but rarely combined both. Our findings indicate that building materials 17



Page 18 of 26

327

with high environmental impacts per kg in China are steel, lime, glass, wood and cement,

328

consistent

329

environmental impact of material use in 2015, midpoint assessment results of both

330

ReCiPe and CML indicate that human toxicity, fossil depletion, and global warming

331

cause the highest environmental impacts as a share of national totals. Based on this

332

finding and the fact that GHG emission burdens are currently the only environmental

333

indicator for evaluating green building material products in the current certification

334

program in China58, other key environmental indicators such as human toxicity and fossil

335

depletion are highly recommended to be included in the certification system.

with

international

studies33,59,60.

However,

when

considering

the

336

Our approach enables us to identify the contribution of specific impact and to see

337

whether it is from a material’s per-unit associated impact or from the magnitude of usage.

338

We exemplify this in Figure 8 for the four major environmental impacts we identified:

339

human toxicity, fossil fuel depletion, climate change and metal depletion in 2015. This

340

visualization shows that although steel, cement, and concrete are key contributing

341

materials for the estimated impacts and have similar magnitudes of Ev, the origin of each

342

impact is different and thus also the potential measures to reduce impacts. Concrete’s

343

impact per kg (Ek) is relatively low and the magnitude of impacts is mostly from the sheer

344

amount used, as seen in Figures 8 panels a and b. In comparison, steel’s high impacts are

345

due to its high per-kg impacts rather than the masses used (panels a, c, and d). Cement’s

346

contributions to impacts are a combination of both the scale of use and the per-kg

347

associated impacts.

348 18


Page 19 of 26


349

2.00 1.00

353

3 2 1

0.00 0.00 0.75 1.50 2.25 3.00 Global warming potential per kg [kg CO2 eq] (c) 4 Annual use [Gt]

354

Annual use [Gt]

352

3.00

0 0.00

(d) 4 Annual use [Gt]

351

(b) 4

(a) 4.00 Annual use [Gt]

350

3 2 1

0.02 0.03 0.05 Human toxicity impact per kg [kg 1,4-DB eq]

0.06

3 2 1

0

0 0

0.25 0.5 0.75 Fossil depletion impact per kg [kg oil eq]

1

0.0

0.2 0.4 0.6 Metal depletion impact per kg [kg Fe eq]

0.8

355 356 357 358 359 360 361 362 363 364

Figure.8 Contribution to key environmental impacts by material. Bubble size represents the magnitude of environmental impact considering the annual material use (Ev) and the location is a function of the per-kg environmental burden (Ek, horizontal axis) and annual material use in 2015 (vertical axis). Presented are Global warming (a), Human toxicity (b), Fossil depletion (c), and Metal depletion (d). Visualizations for the other environmental impacts are included in the supporting information. Note that units differ for the horizontal axes of each panel.

365

Contribution analysis for other impact categories are included in the supporting

366

information Figure S3, further showcasing the variability in impacts by each material.

367

The findings shed light on strategies for mitigate certain environmental impacts. Taking

368

mitigating global warming as an example, reducing the energy use and using less CO2-

369

intensive energy sources in steel and lime production are presumably the most effective 19



370

approaches. Whereas in the case of concrete, gravel, and bricks, the focus should be on

371

reducing consumption or looking for substitute materials with lower GHG burden such

372

as hollow concrete blocks, stabilized soil blocks or fly ash61.

373

Research limitation and suggestion

374

One simplification of data in this study is that building material intensity coefficients are

375

spatially and temporally uniform within our research period 2000-2015. In practice,

376

building material intensity is likely to vary in different climate, geography, urban or

377

rural59,62 settings. Moreover, with transformation of construction technology and

378

technical improvements, building materials composition intensities may change over time.

379

According to Yu and Li63, Chang6,64 and other scholars65, the use rates of steel, cement,

380

and concrete has been increasing in China’s buildings since 1990, while the use of brick

381

has decreased, and the scenarios of Wang et al.66 for buildings in mainland China suggest

382

that by 2050 two out of every three buildings in China will be reinforced concrete or steel

383

framed. Considering that concrete and steel both have high environmental burdens, their

384

increasing use will undoubtedly lead to higher environmental impacts. The scale of

385

change within China calls for further study of the spatial and temporal differences in

386

building material use in order to enable an investigation of the contribution of different

387

changes to the overall development.

388

Among the ten materials discussed in our study, the life cycle inventory of eight

389

come from a domestic source, the Sinocenter database (another two are from Gabi 6

390

database). Sinocenter was released in 2014 and is the only available comprehensive

391

database containing the key building materials in China. Although this is a real 20


Page 20 of 26

Page 21 of 26


392

improvement over using international data which is often not representative of Chinese

393

manufacturing, there is still room for improvement. The available inventories may not be

394

sufficiently representative of historical production processes and so the assessment of the

395

earlier years in our study may have higher uncertainties. Uncertainties also exist in the

396

LCA methodologies we applied. For instance, we adopted the normalization factor of

397

ReCiPe world level 2000 since this is the most recently updated one, and there is no

398

published reference for normalization with respect to China. More updated and local

399

reference factors would allow us to expand the analytical approach we introduce in this

400

study as a tool for identification of associated environmental impacts on the national scale.

401

We use novel, localized data set including the production inventories, the material

402

intensity coefficients, and annual constructed area for each building type at the province

403

level. We include these data in the supporting information, aiming to offer transparency

404

and open data67. These datasets can be used to further explore research topics related with

405

building material use and associated environmental impacts in China. One could expand

406

the estimation period of building materials, including identifying the manufacturing

407

location, the demolition material treatment and recycling actions, to estimate and reveal

408

approaches to enhance the sustainability of building materials in the whole life cycle.

409

Regarding the building material waste, one can estimate the future end-of-life flows

410

(building material waste production amount) if the inflows data (annual building material

411

use) in our study can be integrated with stocks data68, which will be important for policy

412

options in building material waste management and circular economy.

21



413

It would be also important to explore the dynamics between building material use

414

and socio-economic factors69,70, for instance the demographic changes, per capita

415

building material stock, local GDP, and urbanization transformation. Given that China

416

will probably continue its urban expansion in the next 1-2 decades71, it is important to

417

establish future dynamic scenario models to identify the driving forces of the building

418

material use, and further seek strategies for facilitate regional and national sustainable

419

development in the building sector.

420

ASSOCIATED CONTENT

421

Supporting information: Building material intensity index; embodied environmental

422

impact after characterization and normalization applying ReCiPe and CML; Spatial

423

distribution of embodied fossil depletion and human toxicity for building materials

424

(PDF)

425

Data for supporting information (EXCEL);

426

Annual constructed building area at province level from 2000-2015 in China (EXCEL);

427

Production inventory for analyzed 10 building materials (EXCEL);

428

AUTHOR INFORMATION

429

Corresponding author

430

*Email: [email protected]

431

ORCID

432

Beijia Huang: 0000-0002-8325-7447

433

Tomer Fishman: 0000-0003-4405-2382

434

Niko Heeren: 0000-0003-4967-6557 22


Page 22 of 26

Page 23 of 26


435

Weiqiang Chen: 0000-0002-7686-2331

436

Edgar Hertwich: 0000-0002-4934-3421

437

Notes

438

The authors declare no competing financial interest.

439

ACKNOWLEDGMENTS

440

The research work of author Beijia Huang is supported by grant from the National Natural

441

Science Foundation of China (No.71403170). Wei-Qiang Chen acknowledges financial

442

support from the Frontier Science Research Project of Chinese Academy of Sciences

443

(QYZDB-SSW-DQC012).

444

REFERENCES (1) Augiseau, V.; Barles,S. Studying construction materials flows and stock: A review. Resour., Conserv. Recycl. 2017,123,153-164. (2) UNEP. Buildings and climate change: Summary for Decision Makers.UNEP.2009. (4) Othman, AAE. Sustainable Architecture: An Investigation into the Architect’s Social Responsibility. International Conference on Sustainable Human Settlements for Economic & Social Development. 2007. (4) Porhincak, M.; Estokova, A. Comparative Analysis of Environmental Performance of Building Materials towards Sustainable Construction. Chem. Eng. Trans. 2013, 35, 1291-1296. (5) Chang, Y.; Huang, Z.; Ries, R. J.; Masanet, E. The embodied air pollutant emissions and water footprints of buildings in China: A quantification using disaggregated input-output life cycle inventory model. J Clean Prod. 2016, 113, 274-284. (6) He, X.; Liu, Y.; Li, T.; Chen, J. Does the rapid development of China's urban residential buildings matter for the environment? Build. Environ. 2013, 64, 130-137. (7) Huang, T.; Shi, F.; Tanikawa, H.; Fei, J.; Han, J. Materials demand and environmental impact of buildings construction and demolition in China based on dynamic material flow analysis. Resour., Conserv. Recycl. 2013, 72, 91-101. (8) Zhang, H.; Li, L.; Chen, T.; Li V. Where will China's real estate market go under the economy's new normal? Cities. 2016, 55, 42-48. (9) Seungjun, R.; Sungho, T.; Sung Joon, S.; George, F. Evaluating the embodied environmental impacts of major building tasks and materials of apartment buildings in Korea. Renew Sustain Energy Rev. 2017, 73, 135-144. (10) Kapur, A.; Keoleian, G.; Kendall, A.; Kesler, S. E. Dynamic modeling of in-use cement stocks in the United States. J. Ind. Ecol. 2008, 12, 539-556. 23



(11) Fishman, T.; Schandl, H.; Tanikawa, H.; Walker, P.; Krausman, F. 2014. Accounting for the material stock of nations. J. Ind. Ecol. 2014, 18, 407-420. (12)Fishman, T.; Schandl, H.; Tanikawa, H. The socio-economic drivers of material stock accumulation in Japan's prefectures. Ecol. Econ. 2015, 113, 76-84. (13) Tanikawa, H.; Fishman, T.; Okuoka, K.; Sugimoto, K. The weight of society over time and space: a comprehensive account of the construction material stock of Japan, 1945-2010. Ind. Ecol. 2015, 19, 778-791. (14) Heeren, N.; Hellweg, S. Tracking construction material over space and time: Prospective and geo-referenced modeling of building stocks and construction material flows. J. Ind. Ecol. 2018. http://doi.org/10.1111/jiec.12739 (15) Sandberg, N. H.; Sartori, I.; Vestrum, M. I.; Brattebø, H. Explaining the historical energy use in dwelling stocks with a segmented dynamic model: Case study of Norway 1960–2015. Energy Build. 2016, 132, 141–153. (16) Sandberg, N. H.; Brattebø, H. Analysis of energy and carbon flows in the future Norwegian dwelling stock. Build Res Inf. 2012, 40, 123-139 (17) Hu, M.M.; Pauliuk, S.; Wang, T.; Huppes, G.; Voet, EVD.; Müller, DB. Iron and Steel in Chinese Residential Buildings: A Dynamic Analysis. Resour., Conserv. Recycl.2010,54(9), 591–600. (18) Cao, Z.; Shen, L.; Liu, L.; Zhao, J.; Zhong, S.; Kong, H.; Sun, Y. Estimating the in-Use Cement Stock in China: 1920–2013. Resour., Conserv. Recycl. 2017.122: 21–31. (19) Hong, T.; Ji, C.; Park, H. Integrated model for assessing the cost and CO2 emission (IMACC) for sustainable structural design in ready-mix concrete. J. Manag. Eng. 2012, 103, 1-8. (20) Cai,W.; Wan, L.; Jiang, Y.; Wang, C.; Lin, L. The Short-Lived Buildings in China: Impacts on Water, Energy and Carbon Emissions. Environ. Sci. Technol. 2015, 49(24) :13921. (21) Hong, T.; Ji, C.; Jang, M.; Park, H. Assessment model for energy consumption and greenhouse gas emissions during the construction phase. J. Manage. Eng. 2014, 30, 226-235. (22) Ng, S. T.; Chen, Y.; Wong, J. M. W. Variability of building environmental assessment tools on evaluating carbon emissions. Environ. Impact Assess.2013,38, 131-141. (23) Song, J. S.; Lee, K. M. Development of a low-carbon product design system based on embedded GHG emissions. Resour., Conserv. Recycl. 2010, 54, 547-56. (24) Eštoková, A.; Porhinčák, M. Reduction of primary energy and CO2 emissions through selection and environmental evaluation of building materials. Theor Found Chem Environ. 2012, 46, 704-712. (25) Jang, M.; Hong, T.; Ji, C. Hybrid LCA model for assessing the embodied environmental impacts of buildings in South Korea. Environ. Impact Assess. 2015, 50, 143-155. (26) Chang Y.; Ries, R. J.; Wang, Y. Life-cycle energy of residential buildings in china. Energ Policy. 2013, 62, 656-664. (27)Lee, K.; Tae, S.; Shin, S. Development of a life cycle assessment program for building (SUSBLCA) in South Korea. Renew Sust Energ Rev. 2009, 13, 1994-2002. (28) Li, X.; Zhu, Y.; Zhang, Z. An LCA-based environmental impact assessment model for construction processes. Build Environ. 2010, 45, 66-75. (29) Ürge-Vorsatz, D.; Eyre, N.; Graham, P.; Harvey, D.; Hertwich, E. G.; Kornevall, C.; Majumdar, M.; McMahon, J.; Mirasgedis, S.; Murakami, S.; Novikova, A.; Jiang, Y. Energy End-Use: Buildings. In Global Energy Assessment, IIASA, Ed. Cambridge University Press: Cambridge, 2012. (30) Smith, K. R.; Balakrishnan, K.; Butler, C.; Chafe, Z.; Fairlie, I.; Kinney, P.; Kjellstrom, T.; Mauzerall, D. L.; McKone, T.; McMichael, A.; Schneider, M. Energy and Health. In Global Energy Assessment, IIASA, Ed. Cambridge University Press: Cambridge, 2012. (31) Dahlstrom, O.; Sornes K.; Eriksen, S.T.; Hertwich, E.G. Life cycle assessment of a single-family residence built to either conventional or passive house standard. Energy Build. 2012.54, 470-479

24


Page 24 of 26

Page 25 of 26


(32) Wang, J.; Zhang, X.; Huang, Z. Life cycle assessment energy consumption and pollutant emission inventory analysis of construction materials production. Research of Environ Sciences. 2007, 20, 149153. (in Chinese) (33) Thormark, C. The effect of materials choice on the total energy need and recycling potential of a building. Build. Environ. 2006, 41, 1019-1026. (34) Bribián, IZ.; Capilla, AV.; Usón, AA. Life cycle assessment of building materials: Comparative analysis of energy and environmental impacts and evaluation of the eco-efficiency improvement potential. Build. Environ. 2011, 46 (5), 1133-1140. (35) Heeren, N.; Mutel, C.L.; Steubing, B.; Ostermeyer, Y.; Wallbaum, H.; Hellweg, S.. Environmental Impact of Buildings—What Matters? Environ. Sci. Technol. 2015, 49(16): 9832–9841. (36) NBSC (National Bureau of Statistics of China). China Statistical Yearhook on Construction. China Statistics Press, Beijing, 2001-2016 (in Chinese) (37) Hong, L.; Zhou, N.; Feng, W.; Khanna, N.; Fridley, D.; Zhao, Y.; Sandholt, K. Building stock dynamics and its impacts on materials and energy demand in China. Energ Policy. 2016, 94, 47–55. (38) Huang, C.; Han, J.; Chen, W. Q. Changing patterns and determinants of infrastructures’ material stocks in Chinese cities. Resour., Conserv. Recycl. 2017, 123, 47-53. (39) DICS (Department of Investment and Construction); NBS (National Bureau of Statistics). China Statistical Yearbook on Construction, China statistics press, Beijing, 2001-2016. (in Chinese) (40)Zhao, P.; Gong, X.Z; Lin, B.; Jiang, Q. Green building materials evaluation and material selection technology system, China Building Materials Press, Beijing. 2014. (in Chinese) (41) Huijbregts MAJ, Steinmann ZJN, Elshout PMF, Stam G, Verones F, Vieira MDM, Hollander A, Van Zelm R, 2016. ReCiPe2016: A harmonized life cycle impact assessment method at midpoint and endpoint level. RIVM Report 2016-0104. Bilthoven, The Netherlands. (42) Strauss, K.; Brent, A.; Hietkamp, S. Characterisation and Normalisation Factors for Life Cycle Impact Assessment Mined Abiotic Resources Categories in South Africa: The manufacturing of catalytic converter exhaust systems as a case study. Int J Life Cycle Assess. 2004, 11, 162- 171. (43) Bueno, C.; Hauschild, M. Z.; Rossignolo. J. A.; Ometto, A. R.; Mendes, N. C. Sensitivity analysis of the use of Life Cycle Impact Assessment methods: a case study on building materials. J Clean Prod. 2016, 112, 2208-2220. (44) LCA ReCiPe midpoint normalization. http://sites.google.com/site/lciarecipe/normalisation. Accessed on March 28, 2018. (45) Guinee, J. Handbook on Life Cycle Assessment. Springer science and business media. 2002 (46) Feng, L.; Lu, J. The Development of Real Estate Land Market and the Impact Factors of Residential Land Prices in China since 2004. China Land Sciences, 2013, 27, 29-35(in Chinese) (47) ZhongShan Realty Research Center. Zhongshan, Guangdong Real estate market research report. Key Success.2011. (in Chinese) (48) Huijbregts, M A J.; Thissen, U.; Guinee, J B.; Jager, T.; Kalf, D.; van de Meent, D.; Ragas, AM.; Sleeswijk, AW.; Reijnders, L. Chemosphere Priority assessment of toxic substances in life cycle assessment. Part I: calculation of toxicity potentials for 181 substances with the nested multi-media fate, exposure and effects model USES-LCA. Chemosphere. 2000, 41, 541-573. (49) Guo, B.; Geng, Y.; Dong, H.; Liu, Y. Energy-related greenhouse gas emission features in China’s energy supply region: the case of Xinjiang. Renew Sust Energ Rev. 2016, 54 (2047), 15-24. (50) You, P.; Hu, D.; Zhang, H.; Guo, Z.; Zhao, Y. Wang, B.; Yuan, Y. Carbon emissions in the system in China-a case study of residential life cycle of urban building system in China-a case study of residential buildings. Ecol Complex. 2011, 8 (2), 201-212. (51) Dodoo, A.; Gustavsson, L.; Sathre, R. Carbon implications of end-of-life management of building materials. Resour., Conserv. Recycl. 2009, 53 (5), 276-286. (52) Per-capita living space in Guangdong Province. http://www.jiwu.com/news/2538880.html. Accessed on Oct 10, 2018 (53) Shan, Y.L.; Guan, DB.; Zheng, H.R.; Ou, JM.; Li, Y.; Meng, J.; Mi, ZF.; Liu, Z.; Zhang, Q. Data Descriptor: China CO2 emission accounts 1997-2015. Scientific Data. 2018. doi:10.1038/sdata.2017.201 25



(54) Sartori, I. Sandberg, N. H.; Brattebø, H. Dynamic Building Stock Modelling: General Algorithm and exemplification for Norway. Energy Build. 2016, 132, 13-25. (55) Yücel, G. Extent of inertia caused by the existing building stock against an energy transition in the Netherlands. Energy Build. 2013, 56, 134-145. (56) Tanikawa, H.; Fishman, T.; Okuoka, K.; Sugimoto, K. The Weight of Society Over Time and Space: A Comprehensive Account of the Construction Material Stock of Japan, 1945–2010. J. Ind. Ecol. 2015, 19, 778-791. (57) Instruction for promoting green building material standard, certification and labeling http://www.miit.gov.cn/n1146285/n1146352/n3054355/n3057569/n3057573/c5995621/content.html .Accessed on Oct 15, 2018 (58) Guggemos, AA. Horvath A. Strategies of Extended Producer Responsibility for Buildings. Journal of Infrastructure Systems. 2003.9 (2),65 (59) Khasreen, MM.; Banfill, PFG.; Menzies, GF. Life-Cycle Assessment and the Environmental Impact of Buildings: A Review. Sustain. 2009, 1 (3), 534-544 (60) Chan, CK.; Leung, TM.; Ng, WY. A review on Life Cycle Assessment, Life Cycle Energy Assessment and Life Cycle Carbon Emissions Assessment on buildings. Appl Energ. 2015,143 (1), 395-413. (61) Huberman, N., Pearlmutter, D. A life-cycle energy analysis of building materials in the Negev desert. Energy and Buildings. 2008,40,837-848. (62) Berkelmans, L.; Wang, H. Chinese Urban Residential Construction to 2040. 2012, Reserve Bank of Australia (63)Yu, H.; Li, GJ. Construction project investment estimation handbook. Beijing: China Architecture & Building Press,1999 (in Chinese) (64) Chang, Y.; Ries, R. J.; Man, Q.; Wang, Y. Disaggregated I-O LCA model for building product chain energy quantification: a case from China. Energy Build.2014, 72, 212-221. (65) Shi, F.; Huang, T.; Tanikawa, T.; Han, J.; Hashimoto, S.; Hashimoto, S.; Moriguchi, Y. Toward a Low Carbon-Dematerialization Society Measuring the Materials Demand and CO2 Emissions of Building and Transport Infrastructure Construction in China. J. Ind. Ecol. 2012, 16, 493-505. (66) Wang, T.; Tian, X.; Hashimoto, S.; Tanikawa, H. Concrete Transformation of Buildings in China and Implications for the Steel Cycle. Resour., Conserv. Recycl. 2015,103: 205-215. (67) Hertwich, E.; Heeren,N.; Kuczens,B.; Majeau-Bettez, G.; Myers, R.; Pauliuk, S.; Stadler, K.; Lifset, R. Nullius in Verba: Advancing Data Transparency in Industrial Ecology. J. Ind. Ecol. 2018. doi.org/10.1111/jiec.12738 (68) Chen, WQ.; Graedel TE. Improved alternatives for estimating in-use material stocks. Environ. Sci. Technol.2015.49:3048-3055 (69) Baynes, TM.; Muller DB. A Socio-economic Metabolism Approach to Sustainable Development and Climate Change Mitigation. Taking stock of industrial ecology. 2016. Springer, Cham (70) Lin, C.; Liu, G.; Muller DB. Characterizing the role of built environment stocks in human development and emission growth. Resour., Conserv. Recycl.2017,123:67-72 (71) Seto, KC.; Guneralp, B.; Hutyra, LR. Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools. PNAS.2012.109.40:16083-16088

26


Page 26 of 26

Building Material Use and Associated Environmental Impacts in China

Recommend Documents