MONTREAL – Some of the consequences of climate change are now irreversible and it is essential to act more vigorously if we want to stop the negative trends that could drastically worsen the situation.

This is the essence of the message delivered on Tuesday by the Secretary General of the World Meteorological Organization, Petteri Taalas, at a conference organized by the Montreal Council on International Relations (CORIM).

Although Mr. Taalas acknowledges that some weather events are the result of natural events, this is no longer the case in most so-called extreme events. “There is scientific evidence that the forest fires and drought in western Canada would not have been possible without the multiplier effect of climate change,” he gave as an example, noting that the temperature was 15 degrees above normal in this part. from the country.

“We can make the analogy with sports: athletes are capable of achieving certain things, but when they are doped they increase their performance and that is what we did to the environment; We doped the atmosphere (with CO2) and that’s why we start to see more extreme events. ”

Warming doubled in Canada

In fact, scientific data shows that “we have witnessed a 1.2 degree warming so far and will soon be approaching the lower limit of the Paris Agreement.” This lower limit is 1.5 degrees of warming and everything indicates that we will reach it in five years and that “in the 2040s we will be permanently at 1.5 degrees”.

However, this increase is a general average. It varies enormously from place to place and from time to time, as we have seen in the West. “In Nordic countries like Canada, Scandinavia, Russia, Alaska, we will see twice the warming compared to the world average. A warming of 2 degrees will mean 4 or 5 degrees in the northern areas. Even 7 degrees during the winter. Whatever happens, we will face major changes, major impacts on nature, etc. “

Melting of the Arctic: irreversible

One of the impacts that is already clearly visible is the accelerated melting of snow and ice in the Arctic and the Greenland glacier. This thaw has multiple effects on the climate, but it has an immediate effect on the sea level, which so far has risen less than a foot, but it is only the beginning. “In the past, we expected a 30 to 60 cm rise by the end of the century and this rise in sea level will continue for hundreds of years. It is irreversible “, warns the scientist who recalls that,” in the worst case, we could see up to 7 meters of rise in sea level by 2300 “.

Although the melt forecast is uncertain, it reports that the melting rate of the Greenland glacier has doubled in recent years. The irreversible nature of the thaw, which will last “hundreds of years”, according to him, is linked to the fact that CO2 has a very long useful life, hence the absolute need to stop increasing its concentration in the atmosphere. “If we allow the CO2 concentration to increase, it will take thousands of years to return to normal levels.”

Extreme weather works with heat

Petteri Taalas explains that “the ocean stores more than 90% of excess heat. The oceans are warming and their levels are rising and this provides more energy for tropical storms ”, hence the record number of hurricanes in the Caribbean last year. “We can expect to see more and more increasingly intense hurricanes, Category 4 or 5,” warns the planet’s chief meteorologist.

This heat stored in the ocean that contains more water causes more evaporation and, therefore, rain. “According to our estimates, 1 degree of warming translates into 7% more humidity in the atmosphere and that means that when it rains, it rains more. Tropical storm damage is more related to flooding than wind speed, ”he argues.

However, if it is too late to stop the melting of the ice, it is possible to slow down extreme weather events. “We could stop this negative trend. This trend will continue into the 2060s, but if we succeed in mitigating GHGs, we could stem this negative trend and we could stabilize in the 2060s. That’s the good news, but some of these trends will remain with us for centuries to come and into the future. worst case for thousands of years. “

Threatened cities and islands

He notes in passing that the planet has now exceeded 400 parts per million (ppm) of CO2 in the atmosphere and “the last time it happened, about 3 million years ago, the planet was about 4 degrees warmer than today and the level from the sea it was 10 to 30 meters higher than today ”.

However, we are 1.2 degrees warmer, on track to 1.5 degrees soon, and experts are forecasting 2.7 if we don’t brake now.

“So far we are heading towards a 2.7 degree warming, with more rains, which would mean more disasters. It would be better for humanity to reach the lower limit of the Paris Agreement of 1.5 degrees.

“Comparing a warming of 1.5 degrees and a warming of 2 degrees seems minimal, but there is a big difference in the number of disasters, flood problems, droughts, in the number of tropical storms and various impacts on people, ecosystems. and human welfare, he continues. For example, we would lose an important part of our agricultural activity if we exceed 2 degrees. There are estimates that if we go up to 3 degrees, we would lose a large proportion of crop yields globally. “

You can hardly imagine what the worst case scenario could mean for all the major coastal cities in the world. “We saw the impact of Hurricane Sandy on New York City. It could mean rebuilding these cities or relocating them. There is also the risk of losing agricultural land ”.

In addition to the coastal towns, there are many inhabited islands that could disappear completely.

“We must start acting!”

Petteri Taalas does not hide that the time for good speeches is over.

“What is lacking right now are practical commitments. We have not heard many new commitments from member countries and this is our challenge for COP 26 in Glasgow (the next international climate conference that opens at the end of the month).

“The message of the scientific community has been heard, but for concrete actions, we must increase the ambition to reach the limits of Paris.

“We must start acting, he pleads. We have started to move in the right direction. We acknowledge the problem, but we have to push. Getting to 1.5 degrees does not seem realistic to me, but we have the means to do it. “

A little optimism

If there is one thing that allows you to see the proverbial light at the end of the tunnel, it is “to see how high these issues are on the political agenda and how much the leaders of the member countries are talking about. Climate mitigation.”

Also, he says, the worst case scenario no longer exists. “We have managed to reduce emissions a bit and that is why it is no longer considered the worst case.”

“In the last 15 years, 32 countries have reduced their GHG emissions and the first three have been Denmark, the United Kingdom and Finland, which have been able to reduce their emissions by 40% and simultaneously have experienced economic growth.”

Even the United States, seen as violators in such matters, has cut its emissions and met half of its commitments under the Paris Agreement.

“The good news too,” he continues, “is that we have a growing number of private sector players who want to be part of the solution and we have been able to create interesting renewable, wind, and solar energy systems. We have a growing number of automakers who have decided to stop producing gasoline vehicles and switch to electric ones. We have a growing number of players in the financial sector who say they will no longer invest in fossil technologies because there is a risk of losing their money. “

Finally, remember that as consumers we can also play a role by reducing our trips, choosing public transport, choosing electric vehicles, using geothermal energy and heat pumps for heating and air conditioning, reducing the consumption of red meat. and consumption of goods in China, where energy is produced mainly from coal.