在黨代表大會的主要演說上，正在競選參議院席位的前維吉尼亞州州長華納（Mark Warner）表示，共和黨的政策是錯誤的，因為他們已經為美國帶來「兩場戰爭、一個暖化的地球、及一個表示我們來跟中國借錢向不喜歡我們的國家買石油的能源政策。對於能源議題，如果我們真能與外國石油脫勾，我們就能讓國家更安全。我們會開始解決全球暖化的問題，以對的政策在24個月之內，以美國的科技及工人，逐漸建造1加侖可跑100英哩的充電式電油混動車輛（plug-in hybrid vehicles）。」
身為參議院環境與公共事務委員會（Senate Environment and Public Works Committee）主席的加州參議員鮑克瑟（Barbara Boxer）告訴代表們，她從前主席奧克拉荷馬州參議員殷霍夫（James Inhofe）接受主席職務時所說的話：「當我從前一位主席手中拿到議事槌時，我告訴他選舉是有因果關係的」。殷霍夫因為將全球暖化形容為一個「玩笑（hoax）」而出名。
Speaker after speaker at the Democratic National Convention is calling on Americans to elect Barack Obama president because they expect him to build a green economy powered by U.S. renewable energy instead of by foreign oil.
U.S. Senator Hillary Clinton of New York told delegates that she ran for president in part, "To promote a clean energy economy that will create millions of green collar jobs."
"And," Clinton said, "to join with our allies to confront our shared challenges, from poverty and genocide to terrorism and global warming. We need to elect Barack Obama because we need a president who understands that America can't compete in a global economy by padding the pockets of energy speculators, while ignoring the workers whose jobs have been shipped overseas. We need a president who understands that we can't solve the problems of global warming by giving windfall profits to the oil companies while ignoring opportunities to invest in new technologies that will build a green economy," Clinton said.
In keynote address to the convention, former Virginia Governor Mark Warner who is now running for a seat in the Senate, said the Republican policies are wrong because they have brought America, "Two wars, a warming planet, an energy policy that says let's borrow money from China to buy oil from countries that don't like us."
"Look at energy," Warner said. "If we actually got ourselves off foreign oil, we can make our country safer."
"We'll start to solve global warming. And with the right policies, within 24 months, we'll be building 100 mile-per-gallon plug-in hybrid vehicles right here - with American technology and with American workers."
U.S. Senator Barbara Boxer of California, who chairs the Senate Environment and Public Works Committee, told delegates what she said when she accepted the chair from the previous chair, Senator James Inhofe of Oklahoma, who has famously called global warming a "hoax."
"When I took the gavel from the former chairman, I told him that 'elections have consequences.' When we win in November, we'll prove it," said Boxer.
"Instead of protecting polluters, we'll protect our families. Instead of ignoring the experts, we'll fight global warming. Instead of facing Republican roadblocks, we'll have a Democratic majority large enough to ensure healthy communities," she said.
"Instead of a president with an Exxon policy, we'll have a president with an energy policy. This November, we can't afford more of the same," Boxer said. "Let's elect Barack Obama so that the world's economic and environmental leader will clearly be our nation - the United States of America."