QUICK & PULSE

The WMO report highlights the highest CO2 concentration in the atmosphere in 800,000 years and the largest number of displaced people due to extreme events in 16 years

The climate has intensified and reached a new level in 2024, with unprecedented economic and social impacts. Some of these consequences will be irreversible for hundreds or thousands of years, such as the warming of the oceans. This information was released on this Thursday (19/3) in the "State of the Global Climate" report by the World Meteorological Organization (WMO), which warns of the need for urgent actions to contain the planet's warming.

The report was contributed by over 70 experts. One of the main points analyzed is the increase in greenhouse gas concentrations in the atmosphere. In 2023, record levels were reached: CO2 concentration was 151% above the pre-industrial level of 1750, the highest in the last 800,000 years. Methane and nitrous oxide concentrations were, respectively, 266% and 124% above the pre-industrial level.

The consolidated numbers for 2024 are not yet available, but preliminary data indicate that the concentration of these gases continued to increase. Greenhouse gases retain the heat sent from the Sun to Earth and, in excess, disrupt the natural process, raising global temperatures.

In this scenario, 2024 was the warmest year on record, with an average increase of approximately 1.55 °C compared to the pre-industrial period (1850-1900). However, this does not mean that the limit proposed by the Paris Agreement has been exceeded. "The 1.5 °C and 2 °C targets of the Paris Agreement refer to warming over decades, not year by year," the report points out. Nevertheless, the secretary-general of the WMO, Celeste Saulo, warns: "Although a single year above 1.5°C of warming does not mean that the long-term temperature targets are out of reach, it indicates that we are increasing the risks to our lives, economies, and the planet."

The WMO highlights that each of the last ten years has been individually one of the ten warmest ever recorded. Global temperature is one of the main parameters of international climate negotiations, says climate policy expert Stela Herschmann from the Climate Observatory, and the new report from the WMO shows that the rise in temperature is just part of a larger picture: "The document compiles a collection of broken records."

One of the records mentioned is the warming of the oceans, which is already impacting marine ecosystems, causing a loss of biodiversity, and reducing the ability to absorb carbon. This phenomenon also favors the formation of hurricanes and contributes to the rise in sea levels. About 90% of the additional heat retained by greenhouse gases is absorbed by the oceans. "Each of the last eight years has set a new record for ocean heat," the WMO states.

Oceans have also become more acidic (lower pH) due to the increase in CO2 concentration. Approximately 25% of anthropogenic CO2 annual emissions are absorbed by the oceans, reducing the pH at rates not observed in the last 26,000 years. This acidification compromises the oceans' ability to absorb CO2 and impacts food security, affecting fish and other marine organisms. According to the WMO, ocean acidification will continue to increase during the 21st century. Changes in the pH of deep waters are also irreversible on scales of centuries to millennia.

The planet is also facing problems with the melting of ice. On September 11, 2024, the daily minimum extent of sea ice in the Arctic was 4.28 million square kilometers, the seventh smallest on record in 46 years. This minimum was 1.17 million square kilometers below the 1991-2020 average, an area almost the size of South Africa.

In Antarctica, it was the third consecutive year in which the minimum extent was below 2 million square kilometers. The melting of glaciers contributes to the rise in sea level, which reached a new record in 2024. The rate of rise has more than doubled since 1993, from 2.1 mm/year (1993-2002) to 4.7 mm/year (2015-2024). “Even just a few millimeters of rise can have a significant impact on flooding, coastal erosion, and saltwater infiltration into aquifers, putting populations at risk,” warns the WMO.

The reduction of glaciers, especially in the mountain ranges of Asia and the Americas, threatens the water security of millions of people. Although the complete data for 2024 are not yet available, preliminary analyses indicate another year of significant glacial mass loss.

The report also emphasizes the intensification of extreme events, such as heatwaves, storms, floods, and droughts. In Brazil, there was the tragedy of the floods in Rio Grande do Sul and the historic droughts in the Amazon.

Stela Herschmann emphasizes that every fraction of a degree of warming matters to avoid even more intense extreme events, which cause human and economic losses. “The world needs to act faster and with more force. The year 2025 is a crucial opportunity for this,” she affirms. She reminds that 2025 is the year for the nations signatories of the Paris Agreement to present new climate goals (the NDCs, Nationally Determined Contributions) with a focus until 2035. The deadline for submitting these goals was February 10th, but so far, only 10% of the 195 signatory countries have submitted their commitments.

Record climate impacts were also highlighted in the WMO report. Regarding food insecurity, the organization states that the current global food and nutrition crisis is the largest in modern history and is exacerbated by extreme climate events. For example, in Southern Africa, in countries such as Zimbabwe, Botswana, Zambia, and Namibia, the rainfall from January to March 2024 – the harvest period – was more than 50% below the average. There was a crop failure of over 40% for the area planted with corn, and the total grain production decreased by more than 50% compared to the previous year.

Extreme weather events also pushed a record number of forced displacements in 2024, the highest number in the last 16 years. In Brazil, just in Porto Alegre (RS), historical floods displaced about 420,000 people. In West and Central Africa, with a highlight on Chad and Nigeria, floods destroyed or damaged more than 639,000 houses and forced over a million people to leave their homes.

The WMO emphasizes that, in addition to the displacements recorded in 2024, many populations are still facing the prolonged effects of previous disasters, such as the drought in the Horn of Africa, the floods in Burundi and Pakistan, as well as the consecutive storms that hit Madagascar, Mozambique, and Malawi in 2022.

The report also lists fundamental measures to address climate change. Among them, the expansion of early warning systems that allow vulnerable populations to prepare for extreme events. Currently, one-third of the world's population, mainly in less developed countries, still do not have access to such systems.

Reducing greenhouse gas emissions is another important point. "Without immediate and deep reductions in greenhouse gas emissions in all sectors and regions, it will be impossible to keep warming below 1.5 °C," the report warns.

Stela reminds that at COP28 in 2023, countries recognized that to maintain the 1.5 °C target, it would be necessary to abandon fossil fuels in energy systems justly, orderly, and equitably, accelerating action in this decade. However, no concrete progress has occurred since then. On the contrary, oil-producing countries continue to defend new exploration projects, despite fossil fuels being the main global source of emissions.

"For this transition to occur, it needs to be articulated between countries. Each nation has a different reality regarding oil, whether in terms of economic, energy, or historical responsibilities. All of this should be considered when defining the calendar and the next steps of the transition. If we wait any longer, it will be too late," says Stela.

The Secretary-General of the UN, António Guterres, also emphasized the need for immediate action, calling on countries to update their NDCs (Nationally Determined Contributions). "Our planet is sending out warning signals – but this report shows that it is still possible to limit the long-term increase in global temperature to 1.5°C. Leaders must act to make this a reality, taking advantage of the benefits of cheap and clean renewable energy for their populations and economies, especially with the update of national climate plans expected this year," he declared.

Another point addressed in the report was climate financing. "In a scenario transitioning to 1.5 °C, annual investments in climate financing need to increase more than sixfold, reaching nearly US$ 9 trillion by 2030 and an additional US$ 10 trillion by 2050," the document states. (PRISCILA PACHECO)