At the root of the climate change problem is the emission of GHGs, which must be a part of any indicator representing environmental performance in the context of climate change. Emissions of GHGs have an impact on global climate change irrespective of where they are emitted, making emissions reductions in China as valuable as those in United States. Because of the global impact of GHG emissions, climate change mitigation and tracking of related environmental performance must occur at an international level with broad participation.

Emissions Data:

Despite the significant attention being given to the issue of climate change, there are still major gaps in GHG inventories. Data availability varies by location and sector. Emissions data reporting from the industrial sector is widely available for most countries in the world, although even these data contains notable gaps. Though data on carbon dioxide emissions from fossil fuel combustion is gathered on a yearly basis by several international agencies, data for other GHGs is minimal. The International Energy Agency (IEA) produces annual data reports on carbon dioxide emissions from fossil fuel combustion within each country. The IEA reports cover most countries and are considered to be the most reliable sources of emissions data that exists. Data on other GHGs is reported every 5 years. These data are originally provided to the IEA by national statistical offices in OECD countries. In non-OECD countries, they are collected directly from various sources in government and industry. The EPI used exclusively IEA data for its emissions calculations.

In order to capture various aspects of environmental performance on climate change, we assessed three different indicators:

1. Carbon dioxide emissions per person;

2. Carbon dioxide emissions intensity of the industrial sector;

3. Carbon dioxide emissions intensity of the energy sector.

There is no universal agreement on targets for GHG emissions. Based on recent international negotiations within the United Nations Framework Convention on Climate Change (UNFCCC), there will likely be a long-term global target set to 40-60% reduction in emissions from 1990 levels by 2050. On this basis, the 2008 EPI used a median target of 50% reduction below 1990 levels. This target is set to reflect how far a nation is from what the scientific community judges to be a long-term emissions reduction goal necessary to avoid the worst impacts of climate change. This general target is incorporated into 2 of the 3 climate change indicators in order to focus climate change performance on long-term management goals.

The climate change rankings may come as a surprise to some, as there is no obvious relationship between wealth and performance. In general, only wealthy countries have invested in national climate change policies, but these policies alone have not necessarily resulted in measurable emission reductions. In many cases, these policies have not been sufficiently stringent to reduce emissions. In contrast, many developing nations are able to perform well due to low levels of total GHG emissions, despite the fact that this performance is not the result of proactive policy changes. The highest-ranking nations in the climate change category are principally poorer countries with economies based in subsistence agriculture and little industry. The industrialized countries with notably high ranks are Switzerland, Norway, and Sweden. These are countries that have implemented innovative government policies to reduce emissions that have produced measurable results, including taxes on fossil fuels, improvements in energy efficiency, and sustainable forest management. Consequently, these countries have managed to get their GHG emissions per capita closer to global long-term targets relative to other industrialized nations. The laggards on climate change are typically countries with particularly carbon-intensive industry and electricity generation sectors, such as United Arab Emirates and Australia, or countries with high rates of deforestation relative to their small populations. Deforestation occuring in developing nations in the tropics accounts for 1/5th of global emissions each year, which is a substantial fraction of total national emissions for many of these countries. Among wealthy nations, the US and Australia rank lowest with regards to climate change performance. They have very high emissions per capita due to relatively high fossil fuel energy consumption and their failure to implement ambitious GHG emissions reduction policies. It may also be surprising to see a number of least-developed nations scoring very well. While these countries have not necessarily been proactive in combating GHG emissions, they simply do not have high emissions due to limited industrial and transport sectors and slow to non-existent deforestation.

Despite the recent spotlight on climate change, even the best datasets are not completely reliable and have major gaps. Ideal future indicators would contain three principal improvements: 1. Improved emissions data on all GHGs. Currently, emissions data on non-carbon dioxide gases are collected every five years, and even these data are not very reliable. Improved GHG reporting of non-carbon dioxide gases will drastically improve our ability to track environmental performance on climate change. 2. Improved GHG emissions data from all economic sectors. It is worthwhile to dig deeper into the management of GHGs by parsing emissions by specific economic sectors in order to put a spotlight on those sectors where emissions are being successfully managed. The 2008 EPI is able to capture the emissions of two economic sectors: industry and energy. Ideally, however, we would include a broader spectrum of sectors, including transportation, agriculture, forestry, and waste disposal. This expanded dataset would provide a more detailed look into trends within all of the major emitting economic sectors. 3. Improved GHG emissions data from land use, land use change, and forestry. A major source of uncertainty in the available GHG emissions data is emissions from deforestation and changing land use. Emissions from this source are estimated to be between 20-25% of the total annual GHG emissions worldwide (IPCC 2007 WGI), yet the data that exist are problematic. This is an important source of error since a significant portion of emissions from many developing countries is from land use change. Omitting these data therefore heavily favors developing countries.