Climate change and the environment were main themes of the meeting but the leaders were widely criticized for failing to deepen their commitments to greenhouse gas reductions with mid term targets. The G8 leaders called for a global reduction in greenhouse gas emissions by at least 50% by 2050, but also didn't specify a base year (for example, 50% of 1990 emission levels).

Yvo de Boer, who leads the UN negotiations to forge a new climate change treaty, was critical of the lack of a baseline for the 50% reduction target, and that the G8 said nothing about making that goal part of a legally binding convention.

On the final day of the Summit, eight other "major developing economies" from developing countries China, India, Indonesia, Brazil, Mexico and South Africa joined the G8 leaders. These countries refused to accept the G8's vague long-term targets. In a statement, developing nations called on developed countries to take the lead in adopting deep emissions reductions targets. They pledged developing countries would take on quantitative emissions reductions as long as they were facilitated through financing and support for technology transfer from developed nations.