Introduction
During the 2015 IPCC COP21 meeting, countries from around the world agreed that globally GHG emissions are rising rapidly with resulting warming that needs to be limited to a 1.5° C increase over pre-Industrial levels. Asian economies were among those leading the call (Coca, 2015). Asian leadership may be because of the high environmental impact rapid development has brought to the region. Among all regions Asia’s energy use and emissions have risen the most rapidly over the past few decades. From 1990 to 2013, Asia’s cumulative share of total contributions of carbon from fossil fuel, cement manufacture and gas flaring emissions (historically) rose from 9.2% to over 19%, exceeding those of Western Europe of 14.4%, but not yet reaching the contributions of North America of 30%. (Boden et al, 2016). To meet the goal of the agreement, urgent action is needed.
Economic growth and urbanization are highly correlated with energy use and GHG emissions levels (for review see, Seto et al, 2014). Asian economies that have experienced this growth are responding to mitigation needs (Coca, 2015). While studies suggest that there is significant potential for cities to reduce global emissions (Creutzig, et al 2015), effective policies to control GHG emissions, require an understanding of the factors that induce energy use and subsequent GHG emissions at the finest geographic resolution possible (Gurney, et al 2015).
This project identifies the changes in energy use by source (residential, commercial, industrial and transportation) for sub-city scale areal units over time. Socio-economic, political and institutional and biophysical factors (i.e., wealth/income, land use change, population, population density, fuel mix-carbon intensity, energy intensity, transit alternatives, policies, built environment, Heating and Cooling Degree Days, etc.,) help explain changes within each sub-city area and for the different case study city and metropolitan regions.
Asian urban GHG emissions
GHG emissions from the region are significant and the major metropolitan centers are large and growing contributors. In most cases, national and urban emissions are increasing, although the APN research teams identified stable emissions over the past few years in Beijing and Tokyo.
In the rapidly developing cities (Bangkok, BHT), important activities
related to the growth of emissions include: 1) the building of cities
and subsequent creation of concrete-related CO 2 emissions; 2) vehicle
(passenger and freight) use; 3) industrial manufacturing energy use and
industrial processes and 4) low but growing residential consumption.
Within these urban centers there is significant difference among
sub-city units. It seems that industrial centers and new commercial
centers have the highest emissions levels. This is probably due to the
economic activities and demand for transportation in these areas. That
is, industry and transportation are important sectors of GHG emissions
in Asian cities. At the same time, the need for air conditioning should
not be overlooked. The comfort of the population is a critical factor
and given that residential energy use is low, increasing cooling should
be prioritized to increase the quality of urban life, particularly for
lower income groups.
In the more developed Asian cities (Taipei, Seoul and Tokyo),
emissions are related to buildings, transportation and residential
energy use. Emissions from these cities are lower per capita than those
of some rapidly developing cities. For example, Tokyo’s per capita
emissions are lower than those of Beijing. Kuala Lumpur’s emissions per
capita are higher than those of New York City.
Given the differences in CO 2 emission sources, there are different policy options for different types of cities. For example, in more developed cities where emission levels are decreasing, given this high embedded energy and CO 2 in buildings reuse could be an important way to lower emissions and preserve historical infrastructure. This is particularly important given the energy and emissions concentrated in new concrete and steel structures. In cities of rapid growth and industrial development, policies to regulate industries (such as those in the BHT region) are more important than building retrofits.
Potential policy pathways
The major Asian metropolitan centers are leading national low-carbon efforts. The studies in this project identified Tokyo and Seoul as national leaders in carbon reduction strategies. Taipei and Bangkok are also implementing policies. This suggests that some of the major metropolitan cities are leading the region’s efforts in meeting the Paris Agreement. Specific policies for low-carbon development across these centers varies and should do so. Certainly, all cities share the need to reduce emissions from growing passenger car use. While many Asian cities are already dense and compact, the temptation of following the sprawled suburban development model and passenger car pathway is strong. This may be beyond the control of local governments. Japan, for instance, was able to reduce its transportation burden due to national policies that limited car ownership early on during development. Moreover, Japan’s “top runner” program has been successful in encouraging efficiencies in new automobiles. Asian governments could learn from the Japanese model. Tokyo is a livable city with access to all areas through transit.
Industrial development, particularly in cities that are industrial centers, is an important contributor to economic wealth, but emissions from industrial processes can be regulated to help reduce emissions. In this case, both urban planning and city regulations requiring lower emissions is possible. Enhancing laws that encourage energy efficiency in both energy use and industrial processes could help here. Finding ways to lower carbon related consumption is challenging. Some options include enhancing the sharing economy, which has enhanced potential in dense settlements compared to more dispersed spatially organized units and encouraging the circular economy. In parts of Asia the rates of recycling and waste reduction are already high, demonstrating the applicability of this model.
Future research suggestions
The review and papers in the project demonstrate the importance of sub-city and sectorial GHG analyses. The future of urban GHG emissions analysis is certainly a focus on higher resolution spatially disaggregated analyses. Promising studies using satellite images that can pick up CO 2 emission signals are interesting and potentially extremely useful. There will still be the need, however, for consumption related emissions analytics. Nevertheless, identifying neighborhoods and areas of high emissions levels allows urban stakeholders to target these areas for reductions and efficiency exercises.
While the larger cities make up the lion’s share of emissions across the region and the world, they are also typically the most efficient and lower per capita GHG emission urban centers. Interest should also be targeted to medium size and smaller cities. Policies from the larger cities serve as models for other cities and more emphasis could be focused on policy migration from larger to smaller centers. This will probably require a transfer of skills and capacities.
Finally, this research identified the need for more policy-oriented research to identify potential pathways most relevant for different types of Asian cities. There are no one- size-fits-all policies and each city will need to develop low carbon trajectories based upon its particular history and sources of emissions. Therefore, more work is needed to analyze the effectiveness of various policies and the ability of these policies to be transferred to cities of similar type.
Asia will remain the center of industrial activity, population growth and increasing CO 2 emissions over the next few decades. It is therefore urgent to identify ways in which the region’s cities can become more efficient and less polluting. There are both hopeful and threatening trends emerging. Whether the region can leap-frog over the problems experienced by the developed world remains uncertain. Work on urban GHG emissions will continue to play an important role into the medium-term future.