WMO Sounds Global Warming Alarm: 2024 Becomes Hottest Year On Record Amid Rising CO₂, Methane, and Extreme Weather
World Meteorological Organisation report, published in 21st annual Greenhouse Gas Bulletin, has stunned both scientists and the policy community ahead of COP30 in Belém, Brazil.
Published : October 16, 2025 at 4:47 PM IST
New Delhi: The planet is experiencing a climate shift, driven by record greenhouse gas emissions, which is causing an energy imbalance.
The World Meteorological Organisation (WMO) reported that 2024 was the hottest year on record, surpassing the symbolic +1.5°C milestone above pre-industrial levels, and reaching new highs in carbon dioxide levels with rate increases of + 3.5 parts per million (ppm) in the atmosphere - highs that have not been seen since modern monitoring of the atmosphere began in 1957.
The report, published in WMO's 21st annual Greenhouse Gas Bulletin, has stunned both scientists and the policy community ahead of COP30 in Belém, Brazil. The theme of the report is clear: greenhouse gases are substantially increasing, and the planet's natural capacity to remove emissions is weakening, which may trigger a self-reinforcing cycle of heat and adverse weather.
Record CO₂ high - 424 ppm, Highest Rate in History
Global average CO₂ concentrations were at 423.9 ± 0.2 ppm in 2024, or 152% of pre-industrial levels (278 ppm). The increase of 3.5 ppm from 2023 to 2024 is the fastest increase of CO₂ observed in nearly 70 years of modern monitoring.
The WMO scientists state this increase is due to the combination of increased fossil fuel combustion, enhanced droughts due to El Niño, and immense wildfires which both degraded the carbon sinks and re-released stored carbon back into the air. Fires in the Amazon Basin, southern Africa, and parts of Australia were among the worst on record.
“The heat trapped by CO₂ and other greenhouse gases is turbo-charging our climate and leading to more extreme weather,” said Ko Barrett, WMO Deputy Secretary-General.
“Every tenth of a degree of additional warming matters. What we are seeing now is the cumulative result of decades of delay,” she warned.
Methane and Nitrous Oxide Also Break Records
- The two other major long-lived greenhouse gases: methane (CH₄) and nitrous oxide (N₂O), also hit all-time highs.
- Methane reached 1,942 parts per billion (ppb), up 166 % from pre-industrial levels.
- Nitrous oxide rose to 338 ppb, up 125 % from pre-industrial levels.
Together, the three gases account for nearly 98 % of the warming effect of all long-lived greenhouse gases. CO₂ alone contributes about two-thirds of the total warming impact.
At a briefing in Geneva, WMO’s Oksana Tarasova, Senior Scientific Officer and lead author of the bulletin, outlined the grim feedback loop now taking shape. “This gas (CO₂) accumulates in the atmosphere. It has a very long lifetime; every single molecule which is emitted has a global impact,” Tarasova said. She added that roughly half of all human-emitted CO₂ is absorbed by forests, land, and oceans, but those natural buffers are showing signs of exhaustion.
“We rely on natural systems to help us offset our impacts, and those systems are so stressed that they start reducing their help. Trees in the Amazon, for example, became stressed from rising temperatures and lack of rainfall during El Niño. If a tree is under stress, if it doesn’t have water, if temperatures are too high, it simply stops photosynthesising,” Tarasova explained.
The WMO warns that such feedback could push ecosystems toward tipping points, thresholds beyond which changes become irreversible. Melting permafrost, for instance, could release vast stores of methane, further amplifying warming.
“Our actions should be toward emission reduction as fast as possible if we don’t want to see the domino effect,” Tarasova cautioned. “Climate change is not a religion. It’s science.”
El Niño, Wildfires, and the Weakening of Carbon Sinks
The report attributes much of 2024’s CO₂ surge to reduced carbon uptake by land ecosystems and record-breaking wildfires. The 2023–2024 El Niño, a warming of the eastern Pacific Ocean, altered rainfall and temperature patterns across the globe.
Tropical forests in South America, Africa, and Southeast Asia dried out, reducing their ability to absorb CO₂. Droughts intensified in southern Africa and northern Brazil, while heatwaves swept across South Asia and Europe.
Simultaneously, wildfire activity soared, releasing billions of tonnes of CO₂ into the air. According to the WMO, oceans, which absorb about a quarter of all CO₂ emissions, also took up less carbon due to record-high sea-surface temperatures persisting from 2023 into 2024.
“There is significant concern that terrestrial and ocean CO₂ sinks are becoming less effective,” the bulletin notes, “which will increase the fraction of anthropogenic CO₂ that stays in the atmosphere, thereby accelerating global warming.”
Global Temperature Surpasses 1.5 °C Threshold
WMO confirmed that 2024 was the hottest year since records began in 1850, breaking the record set in 2023. The global mean temperature stood at approximately 1.55 °C above the 1850–1900 average, making it the first calendar year to cross the 1.5 °C mark, a key benchmark under the Paris Agreement.
The Paris accord, adopted in 2015, aims to keep global temperature rise “well below 2 °C” and ideally “below 1.5 °C.” WMO experts stress that a single year above 1.5 °C does not yet mean the goal is lost — but it is a clear warning that the window for action is closing.
India’s Balancing Act: Growth vs. Green Responsibility
The findings of the WMO were sharply condemned by climate experts in India, who provided a reminder of how the global crisis has far-reaching domestic consequences. With a population of 1.4 billion and an economy that is already growing, India's challenge is to grow sustainably while cutting down emissions.
"India's rapid industrialisation, expanding cities, and increased energy consumption are globally significant drivers of emissions," Rajesh Solomon Paul, environmentalist and CEO of Excel Geomatics, told ETV Bharat.
"It is necessary for India to continue growing but to reduce emissions, India needs to urgently accelerate the transition away from coal, look at the efficiency of industry, and invest heavily in renewable energy, methane capture, low low-emission agriculture."
Paul pointed out that India's climate policy must balance economic realism at a local scale with environmental urgency. "More robust policing of emissions standards, carbon markets, and incentives for cleaner technologies can allow us to reconcile economic growth with climate action. State governments and industry should focus on local climate action, urban greening, waste-to-energy and sustainable mobility, while individuals adopt energy efficiency and rooftop solar." India can show that development and decarbonisation can go hand in hand if policy, innovation, and public participation move in sync.”
Prof. SN Mishra, Climate Change Consultant and Professor at TERI School of Advanced Studies, described the WMO data as a stark indicator of nature’s diminishing ability to absorb human emissions.
“The rise in CO₂-equivalent concentration is a cumulative outcome of emissions from across the planet. India, though the third-largest emitter in absolute terms, contributes only about one-third of global per-capita emissions and ranks 106th globally on that metric,” he noted.
“Global warming is driven primarily by greenhouse gas emissions from fossil fuels. Yet India is making remarkable progress; over 50% of its installed power capacity now comes from clean and renewable energy sources.”
He explained that a 3.5 ppm rise corresponds to roughly 7.5 gigatonnes of additional CO₂-equivalent emissions in one year, a “massive and worrying jump.”
“This faster increase likely reflects the saturation and declining efficiency of natural carbon sinks. While the rate of emissions growth may be slowing, the atmosphere appears to have entered a self-reinforcing, vicious cycle. Climate change is intensifying, and so are its impacts.”
Mishra urged both systemic and individual action. "Industries must decarbonise by shifting to renewables, recycling materials, and embedding sustainability into their operations. Individuals should choose clean public transport, carpooling, and energy-efficient appliances. Small acts can aggregate into major climate gains," he said.
“India’s factories and cities are pushing us closer to the edge," environmental activist Manu Singh described the UN’s findings as a “painful reminder that time is slipping away.”
“The UN’s warning that 2024 was the hottest year in human history feels like a wound opening before our eyes,” Singh said. “India’s factories, swelling cities, and endless hunger for power are pushing us closer to the edge. We cannot carry on as if nothing is wrong.”
He called for a “massive push” toward clean energy and sustainable urban planning. “We need sharp limits on coal, ways to trap methane in farming, and cities built with nature in mind. Industries should be rewarded for being green, not for cutting corners. And each of us must live lighter, with compassion, demanding accountability. India has to lead, not follow, because our children deserve skies that breathe and rivers that flow free.”
For Bhavreen Kandhari, the crisis is not just about one gas but about a systemic imbalance. “We cannot treat greenhouse gases separately. A holistic emissions strategy: covering CO₂, methane, and nitrous oxide, is imperative,” she said. “That means curbing coal, reforming fertiliser use, capturing landfill gas, and incentivising low-carbon practices across sectors.”
Kandhari argued that India’s rapid urban expansion and surging energy demand are pushing emissions upward, especially from coal power and vehicle use.
“Policy must catch up with growth. India should enforce tighter efficiency norms, mandate cleaner fuels, design low-carbon cities, and strictly vet new industrial projects for climate impact. It’s less about individuals alone and more about structural change: states have a pivotal role.”
She urged state-level carbon budgeting and industrial innovation. “States can pioneer carbon budgets suited to their growth paths. Industries must lead by example: adopt circular economy principles, energy efficiency, carbon offsets, and invest in innovation. Growth need not be emission-intensive if we decouple development from fossil dependence.”
Vikrant Tongad, environmental conservationist and founder of the Centre for Climate Change, highlighted India’s measured but determined approach toward net-zero. “India is among the world’s top five greenhouse gas emitters, but our share in global emissions is just 7%, compared to China’s 30%, the United States’ 15%, the EU’s 6%, and Russia’s 6%. Together, these five account for over 60% of global GHG emissions,” Tongad said.
He pointed out that India’s net-zero by 2070 target aligns with its developmental priorities and poverty reduction goals. “India’s 2070 timeline has been recognised globally as realistic and fair. Abrupt restrictions would harm livelihoods. Instead, India is strengthening environmental policies, improving implementation, and focusing on sustainable growth.”
“We are home to 18% of the world’s population but contribute only 7% of emissions. By pursuing renewables, cleaner industry, and local conservation initiatives, India demonstrates that responsible growth is possible,” he added.
Tongad emphasised that achieving net-zero by 2050 globally, as urged by the UN, will depend on whether the top five emitters meet their pledges.
“If they do, temperature rise can still be limited. Failure to act, however, will bring serious global consequences.”
Dr Hishmi Jamil Husain, an environmentalist, told ETV Bharat, “To effectively reduce emissions, India must focus on six key areas: energy transition, green industry, sustainable infrastructure, clean transportation, smart agriculture, and climate finance.
The first step is accelerating the shift to renewable energy and improving efficiency across sectors. Building green industries and adopting circular economy practices will promote clean manufacturing and sustainable growth. Electrifying transport and expanding the use of EVs can significantly cut air pollution. In agriculture, smart farming techniques and reduced fertilizer use will boost efficiency and lower emissions.
He added, “Equally important are creating natural carbon sinks through afforestation and ensuring adequate funding for green projects. Citizens can contribute by adopting low-carbon lifestyles, conserving energy, and participating in tree-planting drives. Industries must invest in cleaner technologies and transparent emission-reduction programs, while the government should provide strong policies, incentives, and awareness initiatives. Collective action by all stakeholders is essential to achieve a low-carbon, sustainable future.”
The Science: A Planet Losing Its Cool
The WMO bulletin elaborates on the mechanisms driving this acceleration. The pre-industrial CO₂ level (around 278 ppm) represented a balance among the atmosphere, oceans, and land biosphere.
In 2024, that balance was decisively broken, with atmospheric CO₂ now 52% higher than before the Industrial Revolution.
The planet’s energy imbalance: the difference between solar energy absorbed and heat radiated back into space, is increasing, trapping more heat and intensifying extreme events.
From record heatwaves in India and Europe, to floods in China and Brazil, and wildfires across Canada and the Amazon, 2024 saw more than 150 “unprecedented” climate disasters, according to a separate UN analysis.
A Warning Ahead of COP30
The WMO report arrives just weeks before COP30, where nations are expected to present stronger climate commitments. It is both a scientific report and a moral reckoning.
“Achieving net-zero anthropogenic CO₂ emissions must be the focus of climate action,” the WMO stressed.
The organisation also urged nations to expand greenhouse gas monitoring systems, noting that reliable data is essential to verify progress and track feedback loops.
Oksana Tarasova concluded, “Sustaining and expanding greenhouse gas monitoring are critical. We are seeing natural systems respond to stress in ways that amplify warming. Recognising this feedback is essential for supporting and tracking climate action.
The data from 2024 illustrated a harsh reality: humanity is burning through our remaining carbon budget significantly faster than anticipated. In order to give ourselves a 50 % chance of keeping warming to the target of 1.5 °C, global CO₂ emissions need to be reduced by 45 % by 2030 (from 2010 levels), which we are nowhere near achieving with current policy.
Scientists caution that if emissions are not significantly reduced, temperatures could be 2.8 °C or more by the end of the century. This will lock the world into great consequences, from unlivable heat to cthe ollapse of agriculture.
For India, there are two challenges: providing energy access and economic growth for millions, while being on a pathway to clean energy. The country has already installed more than 190 GW of renewable capacity and is targeting 500 GW by 2030, which would be over 50 % of total electricity generation. The electric mobility, hydrogen energy, and afforestation programs are also developing, although experts argue that how well this is done and how quickly it evolves will define success.
As Rajesh Solomon Paul summed up, “India’s transition cannot wait. The science is clear. The choice is whether we lead this transition or get dragged into it by crisis.”
A Planet on the Brink: But Not Without Hope
While the numbers are bleak, scientists are adamant that the crisis is still solvable. Every fraction of a degree avoided will save lives, reduce displacement, and increase the stability of ecosystems and societies. The tools exist: renewable energy, carbon capture, reforestation, efficiency measures, and smarter urban design, but political will and societal participation are lagging.
As the WMO’s Ko Barrett put it, “The science could not be clearer. The longer we wait, the more painful the choices become. But if we act now, decisively, we can still shape the future.”
The planet’s fever has never been higher. But whether it becomes fatal or finally spurs a cure depends entirely on what humanity does next.
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