Wake-up call—Earth’s temperature will rise by two to five degrees warn scientists

Scientists warm how extreme weather conditions look set to become permanent as Earth continues to get warmer and warmer, and the future doesn’t seem to be brighter.

Researchers at the University of Washington have concluded that there is a 90 percent chance that by the end of this century alone, the average temperature of Earth will have risen between 2 and 4.9 degrees Celsius. The results could be catastrophic.

“Damage from weather, droughts, extreme temperatures, and rising sea levels will be much more severe if temperatures are allowed to rise by two degrees or more,” Dargan Frierson, a co-leader of the study published in Nature said in a statement.

“Our results show that it is necessary to make a drastic change of course if we are to achieve the objectives of only raising the temperature by 1.5 degrees – the ideal objective of the Paris Agreement”.

Frierson continued saying: “Countries argued for the 1.5C target due to the severe impacts on their livelihoods that would result from exceeding that threshold. Certainly, damages from heat extremes, drought, extreme weather and sea level rise will be much more severe if 2C or higher temperature rise is allowed on our planet. Our conclusions show that an abrupt change of course is needed to achieve these goals.”

Predictions made by researcher—with the aid of statistical tools—have shown that the probability of reaching the best possible scenario, and not reaching a temperature rise of 1.5 degrees, is minuscule: one percent.

It seems a little more possible not to exceed two degrees, but this probability is only five percent.

What will happen, according to this scientific study, is that the temperature increase will be between 2 and 4.9 degrees with a 90 percent probability.

Even if all greenhouse gas emissions were stopped immediately, by 2100 temperatures would be 1.3 degrees higher, according to these forecasts.

Global carbon emission projections through the year 2100, per year (left) and cumulative (right). Image Credit

“Our results show that the goal of limiting the temperature rise to two degrees is really very optimistic,” said Adrian Raftery, the study’s lead author. “It can be achieved, but only with great efforts on all fronts and over the next 80 years.”

These predictions have been created with computer simulations and, above all, with direct observations of the planet’s climate.

For example, scientists have taken into account the ability of the oceans to absorb carbon dioxide, a major gas that causes global warming, the planet’s energy balance, or the contribution of fine particles to the atmosphere.

In addition to that, researchers have taken very much into account the industrial development of countries.

Scientists used data accumulated over 50 years to create various scenarios based on gross domestic product (GDP), population growth or “carbon intensity”, a parameter that calculates the amount of carbon dioxide emitted by each dollar produced in economic activity. Together, they tried to predict what would happen if things went on as they have until now or if countries made serious efforts to stop burning fossil fuels.

“In short, the objectives of the Paris Agreement are ambiguous but realistic,” Raftery said. “The bad news is that they do not seem to be enough to keep the temperature rise below one-and-a-half degrees.”

According to previous studies made by Raftery, by the end of this century, the world population will be around 11 billion people. This will not have as much impact because most of the growth will occur in Africa, a continent that in comparison with others burns fewer fossil fuels.

So what is the greatest cause?

The authors of the research study concluded that the most important factor will be “carbon intensity”, that parameter that measures the amount of carbon dioxide emitted compared to economic activity.

This parameter improves as the technology becomes more efficient and emits less pollution. For example thanks to the use of better motors or filters we can achieve a much clearer world.

That’s why, according to Adrian Raftery, the speed with which this efficiency increases will be key in determining how bad the climate change will be. But it will not work if countries do not commit to using these technological improvements and trying to reduce emissions as much as they can.

(H/T University of Washington)

Source: Less than 2 °C warming by 2100 unlikely