The people of the world must change their patterns of energy use dramatically and rapidly to avoid dangerous interference with the earth’s climate system. But efforts so far to address the problem have fallen far short of what is needed to address the problem.
That’s the sobering conclusion reached in a new report by the Intergovernmental Panel on Climate Change (IPCC), the international organization of scientists studying the problem.
“There is a clear message from science: To avoid dangerous interference with the climate system, we need to move away from business as usual,” said Ottmar Edenhofer, who helped oversee the group’s roughly 500-page report.
The document is second in the group’s new three-part “assessment” of where the world currently stands in the battle to prevent catastrophic climate change. The first report, issued last year, dealt with the climate science; the second deals with the impacts of climate change.
The report is already putting renewed focus on how people use energy.
“To greatly reduce [carbon dioxide] emissions, we must revolutionize our systems of energy production and consumption,” said energy expert Ken Caldeira of the Carnegie Institution for Science at Stanford.
The carbon footprint of the world’s economy is now the equivalent of about 50 billion tons of carbon dioxide per year. Turning that situation around, the IPCC report says, is like turning a cruise ship. But so far the ship is still charging ahead—emissions in the first decade of this century were higher than the previous 3 decades.
“[T]he main contributors to emission growth were a growing energy demand and an increase of the share of coal in the global fuel mix,” the report’s summary says.
There was a glimmer of good news in the report. From 2000 to 2010, world economies became more efficient in their use of energy. But meanwhile the world’s population grew steadily and energy use became more carbon intensive. As a result, there was a net increase of 7 billion tons of emissions in that decade compared to the previous one.
“There’s nothing that’s happened recently that suggests that we’re coming down,” said Leon Clarke, an author of the report and an economist at the U.S. Department of Energy’s Pacific Northwest National Laboratory in Richland, Washington.
There is general agreement among climate scientists that the concentration of carbon dioxide in the atmosphere needs to stay under 450 parts per million (ppm) to prevent the planet from warming by more than 2°C. The concentration now is about 400 ppm.
The report identifies a number of paths that could lead us to a more stable climate system by 2100. Carbon-free renewable energy production will have to be a major part of any solution, the scientists say.