Integrated studies of coupled human and natural systems reveal new and complex patterns and processes not evident when studied by social or natural scientists separately. Synthesis of six case studies from around the world shows that couplings between human and natural systems vary across space, time, and organizational units. They also exhibit nonlinear dynamics with thresholds, reciprocal feedback loops, time lags, resilience, heterogeneity, and surprises. Furthermore, past couplings have legacy effects on present conditions and future possibilities.
Abstract There is an increasingly hot debate on whether the replacement of conventional vehicles (CVs) by electric vehicles (EVs) should be delayed or accelerated since EVs require higher cost and cause more pollution than CVs in the manufacturing process. Here we reveal two hidden benefits of EVs for addressing climate change to support the imperative acceleration of replacing CVs with EVs. As EVs emit much less heat than CVs within the same mileage, the replacement can mitigate urban heat island effect (UHIE) to reduce the energy consumption of air conditioners, benefitting local and global climates. To demonstrate these effects brought by the replacement of CVs by EVs, we take Beijing, China, as an example. EVs emit only 19.8% of the total heat emitted by CVs per mile. The replacement of CVs by EVs in 2012 could have mitigated the summer heat island intensity (HII) by about 0.94°C, reduced the amount of electricity consumed daily by air conditioners in buildings by 14.44 million kilowatt-hours (kWh) and reduced daily CO 2 emissions by 10,686 tonnes.
Abstract After three decades of exceptional economic growth, China has become a global economic powerhouse. As the economy has grown, though, so have China's environmental challenges, causing enormous socioeconomic consequences for China and the rest of the world. The global financial crisis has prompted China to create more domestic demand for consumption and implement massive infrastructure construction. Although China has the second-largest total gross domestic product (GDP) in the world, its per capita GDP is still much lower than per capita GDP of developed countries: there is much room for further increase in GDP and consequent environmental challenges. Despite China's many efforts to protect the environment and improve resource use efficiency, increasing environmental pollution and resource scarcity have become a severe bottleneck for sustainable development. Because of China's size, these and other challenges and opportunities have huge implications for the world. However, literature related to China's various environmental challenges and rapid changes is scattered. In this article, we outline China's socioeconomic transformation, synthesize China's environmental challenges and their interrelationships, illustrate impacts of environmental challenges on human well-being in China and beyond, and offer a systems approach to addressing environmental sustainability. KEY WORDS: Chinaworldenvionmenteconomic developmentsustainabilitycoupled human and natural systems ACKNOWLEDGMENTS The authors would like to thank William Clark, Peter Gleick, James Hansen, John Holdren, Keping Ma, Pamela Matson, John MacKinnon, Jeffrey McNeely, Mario Molina, Sandra Postel, and Libing Zhang for their great assistance in providing useful information and materials; Joanna Broderick and Shuxin Li for editorial assistance and literature search; and two anonymous reviewers, Xiaodong Chen, Yu Li, Terry Logan, Junyan Luo, Abby Lynch, Megan Matonis, Bill McConnell, James Millington, Nick Reo, Mao-Ning Tuanmu, Andres Vina, Wu Yang, and Chiara Zuccarino-Crowe for reviewing an earlier draft and providing helpful suggestions. Support from the National Science Foundation and the Michigan Agricultural Experiment Station is greatly appreciated.
We thank Goswami et al. (1), Harihar et al. (2), and Karanth et al. (3), for their interest in our study (4). However, unfortunately their critiques are misinterpretations and misrepresentations of our report. Because of space limits, we can only comment on their main points briefly.
Abstract Cities are the engines for implementing the Sustainable Development Goals (SDGs), which provide a blueprint for achieving global sustainability. However, knowledge gaps exist in quantitatively assessing progress towards SDGs for different-sized cities. There is a shortage of relevant statistical data for many cities, especially small cities, in developing/underdeveloped countries. Here we devise and test a systematic method for assessing SDG progress using open-source big data for 254 Chinese cities and compare the results with those obtained using statistical data. We find that big data is a promising alternative for tracking the overall SDG progress of cities, including those lacking relevant statistical data (83 Chinese cities). Our analysis reveals decreasing SDG Index scores (representing the overall SDG performance) with the decrease in the size of Chinese cities, suggesting the need to improve SDG progress in small and medium cities to achieve more balanced sustainability at the (sub)national level.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
