Climate emergency | The IPCC presents its solutions

The IPCC will release a long-awaited report on climate change mitigation on Monday. This roadmap must indicate the way forward to reduce greenhouse gas emissions and achieve carbon neutrality. Overview of the challenges ahead.

Eric-Pierre Champagne
The Press

Another IPCC report?

The Intergovernmental Panel on Climate Change (IPCC) published the third part of its sixth assessment report on Monday. This new report focuses on climate change mitigation measures. You will find there, in a way, the most recent instructions for limiting global warming to 2 ℃ and, ideally, to 1.5 ℃. However, if the trend continues, the planet is heading towards an average warming of 2.7 ℃ by the end of the century.

An increasingly narrow path

The more time passes, the more the “window of opportunity” to achieve the 2015 objectives of the Paris agreement closes. That year, greenhouse gas (GHG) emissions totaled 40.2 billion tonnes and the concentration of CO₂ in the atmosphere peaked at 400.91 parts per million (ppm). Seven years later, the picture has gotten worse.

Short-lived setback

The decline in global GHG emissions in 2020, to 38 billion tonnes, was only short-lived. With global economic activity picking up in 2021, emissions from the energy sector alone totaled 36.3 billion tonnes.

According to the Global Carbon Project, an international group of scientists, 2021 should approach the all-time high of 2019, when emissions totaled 40.5 billion tonnes.

45%

According to the IPCC, we would have to reduce our GHG emissions by 45% by 2030 to limit global warming to 1.5 ℃. In reality, we should instead expect a 16% increase in emissions by the end of the decade, taking into account all the commitments submitted to the Glasgow Summit last November.

420.49ppm

It was the concentration of CO₂ into the Earth’s atmosphere on March 29. This unit of measurement, parts per million (ppm), indicates the number of molecules of CO₂ for every million air molecules. However, the higher the concentration, the higher the temperatures on Earth.

For 800,000 years, the concentration of CO₂ had never exceeded 300 ppm, estimates NASA. This barrier was crossed at the beginning of the XX^and century and has been pushed back ever since. Scientists have calculated that over the past 60 years, the rate of increase in atmospheric carbon dioxide was 1000 times faster than the natural increases that occurred at the end of the last ice age.

450ppm

In 2014, the IPCC estimated 450 ppm as the limit not to be exceeded in order to limit warming to 2 ℃. On February 14, the Mauna Loa station in Hawaii recorded a concentration of 421.59 ppm, a level comparable to that which prevailed between 4.1 and 4.5 million years ago, according to the National Oceanic and Atmospheric Administration (NOAA). Since 1750, the level of carbon dioxide in the atmosphere has increased by 49%.

A carbon budget to respect

What is a carbon budget? Like any budget, the exercise makes it possible to set the level of expenditure not to be exceeded, otherwise it will be in deficit. The carbon budget determines the quantity of GHGs that can be sent into the atmosphere according to the targets set by the Paris agreement.

1.5℃ target

To limit warming to 1.5℃, the world has 420 billion tons of GHGs to spend, with a 50% chance of reaching this goal, according to the latest estimates from the Global Carbon Project. At the current rate of global emissions, this budget would be exhausted in 11 years.

2℃ target

To limit warming to 2℃, the world has 1270 billion tons of GHGs to spend, with a 50% chance of success. At the current rate, this budget would be exhausted in 32 years.

Solutions ?

In addition to the energy transition, the IPCC has already announced that part of its report will be devoted to technology. “Behavioral choices and lifestyles at the individual and societal level will also be addressed”. On this subject, a recent study conducted by researchers at the University of Leeds, in the United Kingdom, made it possible to target a few changes to the Western way of life that would make it possible to reduce global GHG emissions by 25%. Six changes were targeted:

1. Reduce meat consumption as much as possible.
2. Buy only three new clothing items each year.
3. Keep your electronic devices for at least seven years.
4. Fly a short flight (three hours or less) once every three years and a long flight once every eight years.
5. If possible, do without a car, otherwise, keep your vehicle longer.
6. Make a “systematic” change, for example, modify your retirement fund to no longer invest in fossil fuels, review the insulation of your home or your heating system if it runs on oil or gas.

Sources: IPCC, Global Carbon Project, Our World in Data, The GuardianFrance Media Agency