A gigantic, steaming-hot mound of compost is not the first place most people would search for a solution to climate change, but the hour is getting very late. “The world experienced unprecedented high-impact climate extremes during the 2001-2010 decade,” declares a new report from the United Nations' World Meteorological Organization, which added that the decade was “the warmest since the start of modern measurements in 1850.” Among those extreme events: the European heat wave of 2003, which in a mere six weeks caused 71,449 excess deaths, according to a study sponsored by the European Union. In the United States alone, 2012 brought the hottest summer on record, the worst drought in 50 years, and Hurricane Sandy. Besides the loss of life, climate-related disasters cost the United States some $140 billion in 2012, a study by the Natural Resources Defense Council concluded.
We can expect to see more climate-related catastrophes soon. In May, scientists announced that carbon dioxide had reached 400 parts per million in the atmosphere. Meanwhile, humanity is raising the level by about 2 parts per million a year by burning fossil fuels, cutting down forests, and other activities.
At the moment, climate policy focuses overwhelmingly on the 2 ppm part of the problem while ignoring the 400 ppm part. Thus in his landmark climate speech on June 25, President Obama touted his administration’s doubling of fuel efficiency standards for vehicles as a major advance in the fight to preserve a livable planet for our children. In Europe, Germany and Denmark are leaving coal behind in favor of generating electricity with wind and solar. But such mitigation measures aim only to limit new emissions of greenhouse gases.
That is no longer sufficient. The 2 ppm of annual emissions being targeted by conventional mitigation efforts are not what are causing the “unprecedented” number of extreme climate events. The bigger culprit by far are the 400 ppm of carbon dioxide that are already in the atmosphere. As long as those 400 ppm remain in place, the planet will keep warming and unleashing more extreme climate events. Even if we slashed annual emissions to zero overnight, the physical inertia of the climate system would keep global temperatures rising for 30 more years.
We need a new paradigm: If humanity is to avoid a future in which the deadly heat waves, floods, and droughts of recent years become normal, we must lower the existing level of carbon dioxide in the atmosphere. To be sure, reducing additional annual emissions and adapting to climate change must remain vital priorities, but the extraction of carbon dioxide from the atmosphere has now become an urgent necessity.
Under this new paradigm, one of the most promising means of extracting atmospheric carbon dioxide is also one of the most common processes on Earth: photosynthesis.