President George W. Bush did not submit the treaty for Senate ratification based on the exemption granted to China (now the world’s largest gross emitter of carbon dioxide, although emission is low per capita). Bush opposed the treaty because of the strain he believed the treaty would put on the economy; he emphasized the uncertainties which he believed were present in the scientific evidence. Furthermore, the U.S. was concerned with broader exemptions of the treaty. For example, the U.S. did not support the split between annex I countries and others. Bush said of the treaty:

This is a challenge that requires a 100% effort; ours, and the rest of the world’s. The world’s second-largest emitter of greenhouse gases is the People’s Republic of China. Yet, China was entirely exempted from the requirements of the Kyoto Protocol. India and Germany are among the top emitters. Yet, India was also exempt from Kyoto … America’s unwillingness to embrace a flawed treaty should not be read by our friends and allies as any abdication of responsibility. To the contrary, my administration is committed to a leadership role on the issue of climate change … Our approach must be consistent with the long-term goal of stabilizing greenhouse gas concentrations in the atmosphere.”

In June 2002, the Environmental Protection Agency released the “Climate Action Report 2002”. Some observers have interpreted this report as being supportive of the protocol, although the report itself does not explicitly endorse the protocol.^{[citation needed]} At the G8 meeting in June 2005 administration officials expressed a desire for “practical commitments industrialized countries can meet without damaging their economies”. According to those same officials, the United States is on track to fulfill its pledge to reduce its carbon intensity 18% by 2012. The United States has signed the Asia Pacific Partnership on Clean Development and Climate, a pact that allows those countries to set their goals for reducing greenhouse gas emissions individually, but with no enforcement mechanism. Supporters of the pact see it as complementing the Kyoto Protocol while being more flexible.

Here is the official document: http://vienna.usembassy.gov/en/download/pdf/kyoto.pdf

The Administration’s position was not uniformly accepted in the U.S. For example, Paul Krugman noted that the target 18% reduction in carbon intensity is still actually an increase in overall emissions. The White House has also come under criticism for downplaying reports that link human activity and greenhouse gas emissions to climate change and that a White House official, former oil industry advocate and current Exxon Mobil officer, Philip Cooney, watered down descriptions of climate research that had already been approved by government scientists, charges the White House denies. Critics point to the Bush administration’s close ties to the oil and gas industries. In June 2005, State Department papers showed the administration thanking Exxon executives for the company’s “active involvement” in helping to determine climate change policy, including the U.S. stance on Kyoto. Input from the business lobby group Global Climate Coalition was also a factor.

In 2002, Congressional researchers who examined the legal status of the Protocol advised that signature of the UNFCCC imposes an obligation to refrain from undermining the Protocol’s object and purpose, and that while the President probably cannot implement the Protocol alone, Congress can create compatible laws on its own initiative.

 Treaties http://www.senate.gov/artandhistory/history/common/briefing/Treaties.htm The Constitution gives the Senate the power to approve, by a two-thirds vote, treaties made by the executive branch.