The Earth is warming at the fastest rate on record as emissions hit new highs and critical carbon sinks break down.
Carbon dioxide levels are at the highest point in at least 2 million years. While humans continue to pump ever greater amounts of carbon into the atmosphere by burning fossil fuels, the ability of the planet to soak up our emissions is weakening. Degraded by fire and drought, forests that were once carbon sinks are now becoming sources of emissions.
At the same time, a drop in aerosol pollution from coal generators and cargo ships is further driving up temperatures. Aerosols reflect sunlight, with a cooling effect. By cleaning up this pollution, countries have further hastened warming.
From 1970 until 2015, the planet heated up at a rate of 0.2 degrees C per decade. But over the last 10 years, temperatures rose by an unprecedented 0.35 degrees C, according to a new study published in Geophysical Research Letters.
Researchers controlled for the effects of volcanic eruptions, changes in solar output, and El Niño, finding that the recent acceleration in warming is not an aberration caused by natural swings in temperature but is consistent with the predictions of climate models.
Together, the past three years measured 1.5 degrees C warmer than the preindustrial era, putting the world at least temporarily in breach of a key target of the Paris Agreement. While the planet has not officially surpassed the Paris goal, which will be judged according to the average temperature over 20 years, overshoot is imminent. Beyond 1.5 degrees, scientists see a grave risk that the Earth will cross key tipping points, from the dieback of the Amazon rainforest to the thawing of Arctic permafrost, that would further accelerate warming.
“Stopping this trend is in our hands,” the new study concludes. “In the current political climate, however, it is quite possible that warming may continue its fast pace or even accelerate further.” At the current rate, they say, the world will breach the Paris target by around 2030.
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