What to remember from the latest report by UN climate experts

If all the oil, gas and coal deposits currently in service are exploited to their term without carbon capture technology, it will be impossible to maintain +1.5°C. (Photo: 123RF)

Paris — The new report by UN climate experts (IPCC), published on Monday, focuses on the reduction of emissions responsible for global warming, the catastrophic effects of which are already being felt around the world.

The warming compared to the pre-industrial era has already reached 1.1°C while the 2015 Paris Agreement sets the objective of keeping it well below 2°C and if possible 1.5°C.

Here are the key points from this 2,800-page long report, which represents the most up-to-date global scientific consensus on these issues.

Ensuring a peak in emissions in 2025

If greenhouse gas emissions are not significantly reduced by 2030, the 1.5°C target will be “out of reach”.

But current policies are paving the way for a warming of 3.2°C by the end of the century.

Meeting the +2°C target already looks extremely complicated: from 2030 to 2050, emissions would have to be reduced each year, as in 2020, an exceptional year when a good part of the world economy came to a standstill due to COVID-19.

In order not to exceed +2.5°C, emissions will have to peak in 2025, which seems unlikely, the trajectory having started to rise again from 2021, returning to pre-pandemic record levels.

However, at the level of emissions in 2019, the “carbon budget” available to maintain a 66% chance of remaining below +1.5°C would be entirely consumed in eight years.

Replacing fossil fuels…

If all the oil, gas and coal deposits currently in service are exploited to their term without carbon capture technology, it will be impossible to maintain +1.5°C.

Eliminating fossil fuel subsidies could cut emissions by 10%.

Maintaining +2°C implies that 30% of oil reserves, 50% of gas reserves and 80% of coal reserves are not used, unless techniques for capturing and storing the CO2 emitted are developed.

Lost assets could run into the trillions of dollars.

… by low-carbon or neutral sources

To meet the goals of the Paris Agreement, the world must achieve “carbon neutrality” in all respects by 2050.

The capacity of photovoltaic and wind energy increased sharply, by 170% and 70% respectively between 2015 and 2019, thanks to falling costs, public policies and social pressure. But despite these spectacular increases, they together represent only 8% of global electricity production, 21% of low-carbon production.

In total, renewables and low-carbon energies – including nuclear and hydroelectricity – account for 37% of global electricity production, the rest coming from fossil fuels.

Reduce demand

The switch to less carbon-intensive energy must not push structural transformations into the background — soft mobility, electric vehicles, teleworking, insulation of buildings, fewer flights — which would reduce emissions by 40% to 70% by 2050.

“Profound and rapid changes in demand will facilitate short- and medium-term emission reductions across all sectors,” the report says.

Globally, the richest 10% of households account for up to 45% of total emissions.

Muzzle the methane

Emissions of methane, a much shorter-lived greenhouse gas than CO2 but 21 times more potent, contribute about a fifth of global warming.

Leaks in fossil fuel production (through wells or gas pipelines) accounted for around a third of these emissions in 2019. Animal husbandry is also an important source.

Meeting the Paris Agreement means halving methane emissions by 2050 (compared to 2019 levels).

Capture CO2

Even in the best-case scenarios, declining emissions will need to be accompanied by the implementation of carbon dioxide removal (EDC) or “negative emissions” techniques to achieve carbon neutrality.

The possibilities range from the natural capture of CO2, by planting trees for example, to the extraction of CO2 from the atmosphere, a technology not yet developed.

These EDCs should make it possible to offset the emissions of sectors that will not be able to sufficiently reduce their emissions by 2050 – aviation, maritime transport or cement factories – and will also be necessary to hope to restore the situation in the event of the Agreement’s objectives being exceeded. from Paris.

Acting is expensive…

Meeting the +1.5°C target will require investments of 2.3 trillion dollars per year between 2023 and 2052, just for the electricity sector. The figure drops to 1,700 billion for +2°C.

In 2021, 750 billion was spent worldwide on clean energy or energy efficiency, according to the International Energy Agency.

According to the IPCC, rich countries spend two to five times less than necessary and investments in developing countries are four to eight times less than necessary.

Holding the +2°C target would entail a drop of 1.3% to 2.7% in global GDP, compared to the current trajectory, and a drop of 2.6% to 4.2% to hold +1 .5°C.

… do nothing more

However, these estimates of (de)growth do not take into account the foreseeable gains, consequences of the avoidance of climatic catastrophes, food crises or the collapse of ecosystems.

“The benefits of scenarios that limit warming to 2°C outweigh the costs of mitigation measures (of emissions) over the entire 21st century,” the report points out.

The only benefits in terms of public health from a reduction in air pollution – the cause of 7 million premature deaths per year worldwide – would, for example, be of the same order as the investments to achieve this objective.

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