The effects of climate change -increasing extreme events, rising sea levels or falling ice in the Arctic- are already here. Greenhouse gas emissions related to man have raised the global temperature by about one degree Celsius compared to pre-industrial levels, concludes the group of UN advisory scientists on climate change, known by its acronym in English IPCC. The question now is how far it will be reached and what impacts it is willing to take on.
The IPCC warns in a report presented early Monday morning in South Korea (Spanish time) that the warming is likely to lead to an increase of 1.5 degrees Celsius between 2030 and 2052 if the world follows the current rate of emissions of greenhouse gases. This means that there is a risk of breaching the more ambitious goal of the Paris Agreement - to fall below 1.5 in 2100 - in little more than a decade.
To avoid this, there is a need for an "unprecedented" transition and "rapid" and "far-reaching" changes in electricity, agriculture, cities, transport and industry, according to the report. If you want to meet the goal of 1.5, you need a 2030 reduction of 45% of carbon dioxide emissions (CO2) - the main greenhouse gas - compared to the level of 2010. In 2050, these emissions - which mostly come from fossil fuels - must have disappeared, something really complicated.
In fact, the policies that countries put on the table when the Paris Agreement was closed in 2015 - which obliges all signatories to submit emission reduction plans - would lead at the moment to warming up to 3 degrees a end of the century. Hence the "rapid, profound and unprecedented" changes to which the IPCC report points out, in which almost a hundred scientists from 44 countries have participated.
"The good news is that some of the actions that would be necessary to limit global warming to 1.5 degrees are already underway around the world, but they need to be accelerated," Valérie Masson-Delmotte said in a statement. of the coordinators of the report.
When the representatives of almost 200 countries closed in 2015 in Paris the pact against warming, all were clear that the battle to avoid climate change had been lost. Reverting the warming is unfeasible due to the accumulation in the atmosphere of the gases expelled since the Industrial Revolution and, above all, since the 1950s, when coal and oil and gas were added as food for world economic growth.
Therefore, the goal established in the Paris Agreement was "to maintain the increase in average global temperature well below 2 degrees Celsius". Although it was added: "And continue efforts to limit that temperature increase to 1.5". This second figure was included due to the pressure of the most exposed countries, such as the small islands of the Pacific. The signatories of the agreement also commissioned the IPCC with a specific report on the goal of 1.5, which is now presented.
The study - which is based on more than 6,000 scientific references - reviews the effects of an increase of 1.5 and compares them with those of a rise of 2 degrees.
It establishes, for example, that the level of the sea would increase 10 centimeters more when going from 1.5 to 2 degrees. And what consequences would this have? Ten million more people would be exposed to the impacts associated with sea level rise.
The IPCC projects more damage for the human being if it reaches 2 degrees compared to 1.5. There will be more impacts on "health, livelihoods, food security, water supply, security and economic growth". For example, the report suggests that limiting warming to 1.5 compared to 2 degrees would reduce the number of people exposed to climate risks and poverty in "several hundred million" by 2050. Or more incidence of diseases such as Dengue and malaria and changes in their geographical distribution.
In addition, reaching 2 degrees, compared to 1.5, will imply more loss of species and extinctions, more forest fires and the spread of invasive animals and plants. And the almost complete disappearance of warm-water coral reefs; reaching an increase of 1.5 will reduce between 70% and 90%. Two degrees would erase them almost completely.
Energy - electrical sector and transport - is the key in the fight against global warming. The IPCC report goes down to the concrete when it establishes that in order to meet the goal of a 1.5-grade increase to 2100 it is required that in 2050 between 70% and 85% of electricity be from renewable sources, that is, free of greenhouse gas emissions. The study gives an opportunity to natural gas - a fossil fuel - but only if measurements of capture and storage of carbon dioxide (CO) are applied2), although the report also points to the environmental impacts of these techniques. If applied, the IPCC indicates that by 2050, 8% of electricity could be generated with gas. The one who does not give any opportunity is coal, and nuclear energy is mentioned, although only in passing and without setting quotas on that plan.
In the energy sector, the report figures the necessary investments to meet the 1.5 in about 900,000 million annual dollars on average between 2015 and 2050. And figure in 12% more than what is needed for the goal of 1.5 with respect to the 2 degrees.
In the case of transport, the report points to a tremendous shift to meet the objective: the share of low-energy emissions must go from 5% in 2020 to between 35% and 65% in 2050. In the industry, the CO emissions2 they should be between 75% and 90% lower in 2050 than in 2010 levels. Or between 50% and 80% if the objective sought is the 2 degrees.
The authors indicate that exceeding the 1.5 border would imply future dependence on CO capture techniques.2 of the atmosphere to achieve that goal. But they warn that "the effectiveness of these techniques is not demonstrated on a large scale and some techniques may have significant risks for sustainable development."