During his second inaugural address in January, US President Barack Obama vowed to respond to the threat of climate change, expressing that its negligence would "betray our children and future generations”.
His speech on Tuesday was billed as proof of the seriousness with which he took that pledge. Central to his plan to cut greenhouse gasses is an attempt to place the first ever US federal regulations on carbon emissions from existing power plants and future ones. Obama is concerned due to the fact that 40 percent of US carbon dioxide is generated by power plants.
The more we start to rely on natural gas, the more it is going to crowd out renewables from the energey market, and that is a very very large problem. People talk about natural gas like it is going to be a bridge to the future, but if we are not careful it is going to lead us right into a ditch...
The proposal, however, is likely to face challenges from a hostile congress. It will also be fiercely opposed in states that rely heavily on the coal industry.
Obama also promised to open up more US land to renewable energy, and work with developing countries to reduce emissions. He addressed the controversial issue of the Keystone XL pipeline, which would carry 800,000 gallons of tar sands oil every day from Canada to the Gulf of Mexico.
Construction of the pipeline still awaits the president's approval, and environmentalists see that decision as the true test of his commitment to tackle global warming.
The US president said that America has produced more oil and gas than ever before while simultaneously reducing carbon emissions.Obama's plan includes the first federal regulations on carbon emissions from new and existing power plants.
Obama said it was up to the state department to determine whether or not the administration approves plans to build a controversial oil pipeline from the tar sands of Canada down to refineries in the Gulf of Mexico.
Obama also called for an end to tax breaks for big oil companies:
"Billions of your tax dollars continue to subsidize some of the most profitable corporations in the history of the world. My budget once again calls for congress to end the tax breaks for big oil companies and invest in the clean energy companies that will fuel our future."
"Make no mistake, the world still looks to America to lead. We have to all shoulder the responsibility for keeping the planet habitable or we are going to suffer the consequences together," Obama also said.
Is this the moment environmentalists have been waiting for?
Inside Story Americas, with presenter Shihab Rattansi, is joined by guests: Dana Nuccitelli, an environmental scientist and contributor to the Guardian newspaper; and Daniel Kessler, a media campaigner, who works with 350.org to build a global grassroots movement to solve the climate crisis.
"There are assumptions that if the keystone pipeline is not built ... it will not make a significant difference in the net greenhouse gas emissions."
-Dana Nuccitelli, an environmental scientist