The Difference Between 1.5 and 2.0 When it Comes to Climate Change is Huge

January 4, 2018 – The latest projections from 27 different global climate models indicate that a rise of global mean temperatures of 2 Celsius in the next 50 years will increase aridity over 25% of the planet. The projects which were published in the journal Nature Climate Change on January 1, 2018, looked at anthropogenic climate change impacts on aridity. In comparing global warming of 1.5 versus 2.0 Celsius degrees, less than two-thirds of the world’s total land surface would dry out with the former rise versus the latter. That is indeed quite significant.

The study projects climate changes up to the year 2070 and illustrates why the effort to achieve no more than a 1.5 Celsius rise is important. It also should be a wake-up call to national governments that postponing addressing carbon emissions could lead to rapid desertification over a quarter of the planet. Areas most affected will be areas already prone to lower precipitation. Think Australia, the Middle East, much of Africa, and a good portion of Central Asia.

The research defines the time of emergence for aridification (ToEA). The 27 global climate models used come from 11 different countries and are consistent in showing where ToEA occurs. The variations in the models range from 24 and 32% of the Earth’s total land surface being impacted over a 50 year period. The models come from the following organizations:

In their conclusions, the researchers are direct in advising “early action for accomplishing the 1.5 Celsius temperature goal” to “markedly reduce the likelihood that large regions will face substantial aridification and related impacts.” 

In other words, if we stay within the 1.5 Celsius upper limit the people, animals, and plants of this planet can largely continue to thrive with little disruption. But if we reach 2.0 Celsius or higher, all bets are off as runaway desertification will leave enormous swaths of the planet barren.

The picture below is not the prettiest to start the New Year off. But none of us can look at it and say we would be satisfied with this end result because we didn’t institute policies and strategies early enough to not let it happen.


When 27 different climate models were put through their paces looking at the global impact delta between a 1.5 and 2 Celsius rise, a picture emerged that has frightening implications. Much of Earth could turn into desert within a very short period.

Len Rosen lives in Toronto, Ontario, Canada. He is a researcher and writer who has a fascination with science and technology. He is married with a daughter who works in radio, and a miniature red poodle who is his daily companion on walks of discovery. More...