The study by Greenpeace - Comparing the two biggest emitters: US/China - sets out a comparison between the world's two largest greenhouse gas emitters. It looks at publicly available data on statistics like CO₂/total primary energy supply; CO₂ emissions per capita; renewable energy targets; and Investments in green recovery.

According to Greenpeace, the report reveals that while China is often perceived as a big, irresponsible polluter, the top level results of the review actually reveal that:

• China has set national goals for renewable energy (15% by 2020) but the US has not set renewable energy targets at Federal level. Instead, 28 states have set renewable portfolio standards with variable levels and target years;
• Chinese fuel economy standards are significantly stricter than those of the US. Chinese cars have already reached the level of efficiency the US aims to achieve by 2016, under President Obama's newly established fuel economy standards;
• China has directed a bigger share of its stimulus money into green jobs and clean tech industry development.

Energy Intensity

China's energy supply is more carbon intensive than that of the US, says the report. However, "China has begun to reduce its carbon intensity, and Chinese President Hu Jintao pledged at the UN in September to reduce carbon intensity by a 'notable margin' by 2020 at 2005 levels".

• Chinese energy supply creates 25% more emissions per energy unit than the US;
• China's carbon intensity per GDP is 20% higher than the US;
• From 1991 to 2002, China reduced its CO₂ emissions per unit of GDP twice as fast as the US. Between 2002-2006 this trend reversed;
• China reduced its economy's carbon intensity faster than the US between 1991 and 2006 (according to official energy statistics from the US Government). 

Per capita emissions

When looking at who should do what to cut greenhouse gas emissions fairly (the crucial component of the COP15 summit in Copenhagen later this year), it is important to look at the amount of emissions per person, says Greenpeace, both now and since the world recognised the climate problem in 1990.

• In 2007, CO₂ emissions per person in the US were almost four times higher than China in the energy industry sectors;
• The US has emitted 7 times more CO₂ emissions per person than China since 1990 (the base year for the UN climate convention);
• US citizens have 26 times more private cars per person than Chinese Citizens.

The report concludes by saying that the USA is in a better place to act than China: " The US ranks 12th in the global human development index, whereas China ranks 81st; the purchasing power of a Chinese citizen's income is, on average, 12.8% of a US citizen; and in 2008 the US had almost 8 times higher GDP per capita in international dollars, compared to China".