President Obama said he believes the clean energy economy that developed during his eight years in the White House will be "irreversible," due in large part to hydraulic fracturing (fracking) driving down the cost and pollution associated with power generation.
In a column posted online Monday in the journal Science, a publication of the American Association for the Advancement of Science (AAAS), the president also urged President-elect Donald Trump to stay the course and continue U.S. participation in talks on climate change.
"Putting near-term politics aside, the mounting economic and scientific evidence leave me confident that trends toward a clean energy economy that have emerged during my presidency will continue and that the economic opportunity for our country to harness that trend will only grow," Obama said.
Media reports said AAAS editors believe Monday's column is the first it has ever published by a sitting president; Obama's term ends on Jan. 20.
According to Obama, carbon dioxide (CO2) emissions have fallen 9.5% from 2008 to 2015, while the economy grew more than 10%. During the same time frame, the president said the amount of energy consumed per dollar of real gross domestic product (GDP) fell by nearly 11%, while the amount of CO2 emitted per unit of energy consumed fell 8% and CO2 emitted per dollar of GDP declined 18%.
But Obama warned that "evidence is mounting that any economic strategy that ignores carbon pollution will impose tremendous costs to the global economy and will result in fewer jobs and less economic growth over the long term." Global warming of 4 degrees Celsius over pre-industrial levels could cause economic damage ranging from 1-5% of global GDP each year by 2100, he said.
"It is becoming increasingly clear that, regardless of the inherent uncertainties in predicting future climate and weather patterns, the investments needed to reduce emissions -- and to increase resilience and preparedness for the changes in climate that can no longer be avoided -- will be modest in comparison with the benefits from avoided climate-change damages," Obama said.
The president said tougher fuel economy standards enacted during his administration are projected to cut more than 8 billion tons of carbon pollution over the lifetime of new vehicles sold between 2012 and 2029. Meanwhile, 44 appliance standards and new building codes are projected to cut another 2.4 billion tons of carbon pollution and save consumers $550 billion by 2030.
Although he never mentioned fracking by name, Obama credited "new production techniques" with increasing supplies and driving down prices. In the power sector, the largest source of greenhouse gas (GHG) emissions in the U.S. economy, natural gas was displacing coal as a power generation fuel source, which in turn was leading to lower GHG emissions.
"Because the cost of new electricity generation using natural gas is projected to remain low relative to coal, it is unlikely that utilities will change course and choose to build coal-fired power plants, which would be more expensive than natural gas plants, regardless of any near-term changes in federal policy," Obama said, in a thinly-veiled reference to Trump's campaign pledge to help the coal industry.
"Although methane emissions from natural gas production are a serious concern, firms have an economic incentive over the long term to put in place waste-reducing measures consistent with standards my Administration has put in place, and states will continue making important progress toward addressing this issue, irrespective of near-term federal policy."
Obama also warned Trump that the United States would "lose its seat at the table to hold other countries to their commitments, demand transparency, and encourage ambition," if it decided to walk away from the climate change, including the meetings that were held in Paris in 2015.
"This should not be a partisan issue," Obama said. "It is good business and good economics to lead a technological revolution and define market trends. And it is smart planning to set long-term emission-reduction targets and give American companies, entrepreneurs, and investors certainty so they can invest and manufacture the emission-reducing technologies that we can use domestically and export to the rest of the world."
That said, Obama emphasized that Trump is free to make his own decisions on the nation's energy policies.
"One of the great advantages of our system of government is that each president is able to chart his or her own policy course," Obama said. "And President-elect [Trump] will have the opportunity to do so. The latest science and economics provide a helpful guide for what the future may bring, in many cases independent of near-term policy choices, when it comes to combating climate change and transitioning to a clean-energy economy.”