The GAO found that the cap-and-trade scheme sucessfuly created a working carbon market, "but its effects on emissions, the European economy, and technology investment are less certain." The report noted that the use of carbon offsets can "undermine the system's integrity" because there is no way to ensure that the projects invested in would not have been built anyway, or that they will last long enough to reduce the amount of emissions that they are expected to reduce. Carbon offsets, the report concluded "involve fundamental tradeoffs and may not be a reliable long-term approach to climate change mitigation."

Greenpeace is deliberately misleading the public into thinking that wind and solar energy, both of which are inherently intermittent and unreliable, can replace baseload power that is continuous and reliable. Only three technologies can produce large amounts of baseload power: fossil fuels, hydroelectric plants and nuclear power. Given that we want to reduce fossil fuels and that potential hydroelectric sites are becoming scarce, nuclear power is the main option. But Greenpeace and its allies remain in denial despite the fact that many independent environmentalists and now the IPCC see the situation clearly. Over the past 10 years, Germany and Denmark have poured billions of taxpayers' euros into wind and solar energy in the vain hope that this would allow them to shut down fossil fuel and nuclear plants. They have not succeeded because every solar panel and every wind turbine must be backed up by reliable power when the sun isn't shining and the wind isn't blowing. ...Greenpeace and company are stuck in the 1970s when it comes to the policy on energy as it relates to climate change.