UN climate scientists mark the roadmap to cut emissions in half by 2030: "It's now or never"

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"It's now or never".

Scientists from the IPCC, the intergovernmental group of experts on climate change linked to the UN, believe that it is still possible to contain the increase in temperature to 1.5 ºC by the end of the century [relative to what it was at the beginning of the industrial era ], but the action must be "immediate" and "significant".

, assured the head of the IPCC, Hoesung Lee, who this Monday presented the third and final part of his Sixth Great Assessment Report, the largest analysis on climate change that serves also as a working document for politicians during climate negotiations.

It has been the last part and also the one that has raised the most objections

, since it focuses on the mitigation measures that must be adopted to combat climate change, mainly the reduction of greenhouse gas emissions.

The text prepared by IPCC scientists based on an exhaustive review of the research available since 2014, when the Fifth Assessment Report was published, is approved after two intense weeks of work in which it has had to reach a consensus with representatives of the almost 200 countries participating in climate summits.

and they have lasted until Sunday night, forcing the publication of this third part of the Sixth Report to be postponed for several hours.

The first part, focused on the science of climate change, was published on August 9, 2021, while the second dealt with the impacts and was launched on February 28.

To achieve the 1.5ºC goal,

(a third in the case of methane).

If we achieve carbon neutrality (or zero emissions) by 2050, the temperature would rise by just 1.5°C by the end of the century.

If we wait until 2070, it would rise to 2°C, according to the report.

The objective reached in the Paris Agreement was to do everything possible so that it does not rise more than 2 ºC (it has already increased 1.1 ºC) although, as has been made clear at the last UN Climate Summit, held in Glasgow , the current commitments of the countries are insufficient to limit it to 1.5 ºC.

In the midst of war with Ukraine, with the planet plunged into an energy crisis and with countries seeking alternatives to fossil fuels that they buy from Russia, IPCC scientists recall that "limiting global warming

, including a substantial reduction in the use of fossil fuels, widespread electrification, improved energy efficiency and the use of alternative fuels such as hydrogen.

They also recall that "since 2010, the costs of solar and wind energy and batteries have been reduced by up to 85%.

According to the scientists' calculations, in order not to exceed 1.5 ºC in 2050, it will be necessary to stop using coal by that year, while the use of oil will have to be reduced by 60% and that of gas, by 70%.

"Even if we do this, it's almost inevitable that we will temporarily exceed that temperature, but we could get it down by the end of the century," say the authors.

Priyadarshi Shukla, co-director of IPCC working group III, considers that "the implementation of appropriate policies, infrastructures and technologies to facilitate changes in our lifestyles and our behavior could translate into a reduction in greenhouse gases between 40 and 70% by 2050" which, furthermore, "would improve our health and well-being".

As Xavier Lavandeira, Professor of Economics at the University of Vigo and one of the Spanish researchers who participated in this installment, explains to EL MUNDO, "it is a very extensive report because it not only covers an immense field but also does so from various perspectives (economic, engineering, political science, etc.)".

Although he warns that it is difficult to summarize its content in a few ideas, he considers that several relevant messages can be extracted from the evaluation of the scientific knowledge generated in recent years: "The first, that

carried out carried out by some countries or sectors. The second is that

: by applying the available options for mitigation, we could substantially reduce emissions by 2030 at affordable costs. The third is that

, in particular keeping the temperature below 1.5ºC,

That objective will be out of our reach unless we introduce emission reduction measures immediately and in all sectors of activity and regions", summarizes Lavandeira, who in this report has been editor reviewer of chapter 13, dedicated to policies and national and subnational climate institutions.

"We are at a crossroads. The decisions we make now can ensure a future in which we can live,"

said Hoesung Lee, who claims to feel "encouraged by the climate actions undertaken in many countries."

They are policies, regulations and market instruments that have proven to be effective, according to Lee: "If their use is expanded and extended, they can help reduce emissions significantly and stimulate innovation," he pointed out.

Among the specific actions mentioned in the report, the potential of cities and other urban areas to reduce emissions by achieving more compact cities in which citizens can walk, electrify transport, in combination with low-emission energy sources stands out.

Using materials more efficiently, reusing them, recycling products and minimizing waste are among the measures to reduce emissions in the industry, which is responsible for a quarter of global emissions.

The IPCC recognizes that achieving zero emissions for such a sector will be challenging and will require new production processes, low-emission electricity, hydrogen and, if necessary, carbon capture and storage.

INCREASE IN EMISSIONS

Anthropogenic greenhouse gas (GHG) emissions, that is, generated by human activities, have continued to grow during the 2010-2019 period, with an increase in all main economic sectors, according to the IPCC report.

The annual average has been higher between 2010 and 2019 than in the previous decade, although the growth rate has been lower.

Anthropogenic emissions include CO2 from the burning of fossil fuels and industrial processes, CO2 from land use, such as agriculture, livestock, land use change or forestry, and emissions of other greenhouse gases: methane (CH4), nitrous oxide (N2O) and fluorinated gases (HFCs; PFCs, SF6, NF3).

If we look at the amount of emissions accumulated since 1850, when industrial activity began,

North America, Europe, Australia, Japan and New Zealand have emitted 43% of historically recorded emissions despite the fact that 22% of the world's population lives in these regions.

Africa and Southeast Asia, with 61% of the world's population, are responsible for 11% of emissions.

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