WE'VE ALREADY HIT THE 1.5 DEGREE C GLOBAL WARMING CEILING THAT WE'VE AGREED NEVER TO GO BEHOND

Meeting in Paris last year, representatives from 195 nations agreed to work together to limit global warming to 1.5 degrees C (2.7 degrees F) above the temperature that prevailed before the industrial revolution. Scientists and policy members agreed that global warming beyond that level creates unacceptable levels of risk to the environment and civilization--much like revving your car's engine into the red zone. The Paris Agreement (Accord de Paris) went into effect in November of 2016.

Negotiators celebrate Paris Agreement 4/22/16

Credit: UN

In what should serve as a three-alarm wake-up-call, researchers at the European Centre for Medium-Range Weather Forecasts, a prestigious independent intergovernmental organization, reports that Earth hit that 1.5 degree C ceiling for the first time in February of 2016 (see section 10 in the above link).

Global Temperatures 1880 to Present

Credit: NASA GISS

The researchers are quick to note that the early months of 2016 were exceptionally warm, following a strong El Niño, and that Earth has cooled approximately 0.3 degrees C (0.5 degrees F) since then. However, with the levels of carbon dioxide (CO2) and other greenhouse gases in Earth's atmosphere continuing to rise, it's only a matter of time before we don't just bump against the 1.5 degree ceiling, but crash through it.

And not much time. The Berlin-based Mercator Research Institute on Global Commons and Climate Change (MCC) calculates that under the most optimistic assumptions, we have only 4 years before we lock in more than 1.5 degrees C of warming, and under the most pessimistic assumptions, just one year.

Atmosperic CO2 levels over the last 500,000 years/Credit NASA

"It is salutary that the world touched the 1.5 degree C level less that twenty years after touching the 1 degree C level in the record-breaking year of 1998," says Adrian Simmons, the study's lead author. 

"Salutary" is a polite, understated, British way of saying that if we value Earth's health and our own, we'd better pay attention and take action.

(Note 1/10/17: I hate to be pessimistic, but it's clear from Trump's own statements and his appointees that the US government will be leading a climate-change charge, but in exactly the wrong direction--away from wind and other renewable sources of energy, and back towards coal and other greenhouse-gas belching technologies.)