The global climate and weather monitoring organization observed that during El Niño years, CO2 levels tend to rise because the efficiency of land carbon sinks is reduced by drier vegetation and forest fires, as was the case with the exceptional drought and fires in the Amazon and southern Africa last year.
By Salam Rajesh
The dialogue on the triple planetary crises – global warming, climate change and extreme weather events – appears to be getting more complex and complicated for the ordinary humans, with the disturbing news that planet Earth is likely to become exceedingly warmer than usual.
This disheartening piece of information is reflected in the latest report of the World Meteorological Organization (WMO) with the release of its Greenhouse Gas Bulletin (WMO, 15 October). The bulletin noted with some concern on carbon dioxide (CO2) levels in the atmosphere soaring considerably last year, bringing the planet to a crisis level with more long-term temperature increase.
The WMO’s bulletin stressed that continued emissions of CO2 from anthropogenic activities and with an upsurge from recent large scale wildfires were primarily responsible for the increased global temperature rise. Additionally, reduced CO2 absorption by ‘carbon sinks’, such as land and wetlands ecosystems, and the ocean, is contributing to the process, the bulletin noted.
WMO re-emphasized that the growth rates of CO2 have tripled since the 1960s, accelerating from an annual average increase of 0.8 ppm per year to 2.4 ppm per year in the decade from 2011 to 2020. From 2023 to 2024, the global average concentration of CO2 surged by 3.5 ppm, the largest increase since modern measurements started in 1957, according to the WMO bulletin.
The organization’s Deputy Secretary-General Ko Barrett observed that the heat trapped by CO2 and other greenhouse gases in the atmosphere is turbo-charging Earth’s climate and is leading to more extreme weather. Barrett further emphasized that reducing emissions is, therefore, highly essential not just for the planet’s climate but also for the economic security and community well-being of all people on this planet. It had been stressed in several reports that continued global temperature rise is giving rise to increased frequency in extreme weather events all across the globe, causing damaging results in terms of human lives and livelihoods, properties, lands, ocean, infrastructure and the wildlife. Adding to the news of gloom is the assertion that the concentrations of methane and nitrous oxide, the second and third most important long-lived greenhouse gases related to human activities, have also risen to record levels.
When the bulletin was first published in 2004, the annual average level of CO2 measured by WMO’s Global Atmosphere Watch network of monitoring stations was 377.1 ppm. In 2024, it was 423.9 ppm. The bulletin noted that around half of the total CO2 emitted each year remains in the atmosphere and the rest is absorbed by Earth’s land ecosystems and oceans. However, this storage is not permanent.
As global temperature rises, the oceans absorb less CO2 because of decreased solubility at higher temperatures, while the land sinks are impacted in a number of ways including the potential for more persistent drought, the bulletin stressed.
The likely reason for the record growth of carbon dioxide between 2023 and 2024 was a large contribution from wildfire emissions and a reduced uptake of CO2 by land and the ocean last year which was recorded as the warmest year on record in a century, with a strong El Niño in the backdrop, according to WMO.
The global climate and weather monitoring organization observed that during El Niño years, CO2 levels tend to rise because the efficiency of land carbon sinks is reduced by drier vegetation and forest fires, as was the case with the exceptional drought and fires in the Amazon and southern Africa last year. WMO senior scientific officer, and the Greenhouse Gas Bulletin coordinator, Oksana Tarasova reflected that there is concern that terrestrial and ocean carbon dioxide sinks are becoming less effective, which will increase the amount of CO2 that stays in the atmosphere, thereby accelerating global warming. Sustained and strengthened greenhouse gas monitoring is critical to understanding these loops, Oksana said.
Accounting methane for about 16% of the warming effect on Earth’s climate by long-lived greenhouse gases, with a lifetime of about nine years, the WMO bulletin noted that approximately 40% of methane is emitted into the atmosphere by natural sources (for example, wetlands) which are sensitive to climate as well, and about 60% comes from anthropogenic sources such as cattle, rice farming, fossil fuel exploitation, landfills and biomass burning.
The globally averaged methane concentration last year was 1942 parts per billion (ppb) which was an increase of 166% above the pre-industrial (before 1750) levels, the bulletin noted.
Nitrous oxide is the third most important long-lived greenhouse gas and comes from both natural sources and due to human activities such as biomass burning, fertilizer use and various industrial processes. The globally averaged concentration of this greenhouse gas reached 338.0 ppb last year, an increase of 25% over the pre-industrial level according to the WMO bulletin.
WMO released its annual greenhouse gas bulletin to provide authoritative scientific information for the UN Climate Change conference (COP 30) later next month. The climate conference in Belém, Brazil, would seek to ramp up climate action. The WMO Global Atmosphere Watch Program coordinates systematic observations and analysis of greenhouse gases and other atmospheric constituents. Greenhouse gas measurement data are archived and distributed by the World Data Centre for Greenhouse Gases (WDCGG) at the Japan Meteorological Agency.
(Salam Rajesh Imphal-based media professional, environmental activist, researcher, and writer on socio-environmental issues in Manipur.)