Our new scientific assessment of how humans are affecting the climate is nothing short of alarming, yet it does contain some encouraging news.
The second “Indicators of Global Climate Change” report, published in Earth System Science Data, provides an annual update on a set of metrics originally assessed by the Intergovernmental Panel on Climate Change (IPCC).
With the latest IPCC assessment report on climate science completed in 2021 and the next one not expected until at least 2027, there is a substantial gap to fill.
This is crucial at a time when human activity is changing the climate system at a rate and scale not experienced since records began.
For 2023, which smashed the record for the warmest year, our best estimate of the warming caused by human activity is 1.31C above pre-industrial levels.
This is the first year where this estimate has reached the 1.3C threshold. Our report also shows that human-caused warming has been increasing at a rate of 0.26C per decade.
This high rate of warming is caused by a combination of greenhouse gas emissions being close to an all-time high and a reduction in the cooling impacts of aerosols as society tackles deadly air pollution.
Yet, there is some positive news: greenhouse gas emissions have not yet risen beyond pre-pandemic levels and there is evidence that the rate of increase in CO2 emissions over the past decade has slowed compared to the 2000s.
Tracking climate change
We track and document how datasets and methods evolve between IPCC report cycles. The aim is to increase transparency and consistency from one cycle to the next, as well as filling the gap between reports.
This takes an international team of more than 50 scientists, including former IPCC authors and curators of global datasets.
The work builds a chain of evidence from emissions to temperature change, bringing around 20 global datasets together, to make a consistent estimate of human-caused warming based on the best-available current data and science.
The data and their changes are displayed on a dedicated Climate Change Tracker platform, shown below.
Greenhouse gas emissions
The starting point for updating the indicators is data on greenhouse gas (GHG) emissions. The most recent decade we have data for (2013-22) shows that average global GHG emissions were equivalent to 53bn tonnes of CO2 (GtCO2) per year.
Total GHG emissions remain ever so slightly below the pre-pandemic high set in 2019, as the chart below illustrates.
With emissions rebounding in the wake of the Covid-induced lockdowns around the world, it is too early to say whether GHG levels have already peaked. For example, both CO2 emissions from coal and gas and emissions of non-CO2 gases are rising. Emissions from oil are also increasing again, but remain below pre-pandemic levels.
These growing emissions have been offset by a small decline in land-use emissions.
With the high levels of ongoing emissions, GHGs have continued to build up in the atmosphere. These in turn affect the heat gained by the Earth system, which is increasing its effective radiative forcing (ERF).
ERF resulting from human activity rose to 2.79 watts per metre squared (W/m2) in 2023, compared to 2.72 W/m2 in 2019. However, last year’s ERF is lower than 2022’s (2.91 W/m2), mainly because of the increase in aerosols from wildfires in 2023, which had a cooling effect. In 2023, the increased aerosols from wildfires more than compensated for the ongoing fall in sulphur emissions from shipping and other sources. (See sections below for more detail.)
Warming impact
High GHG emission levels are also affecting the Earth’s energy balance, with observations showing an increase in the rate of heating on land and in oceans. Satellites and ocean buoys are tracking unprecedented flows of heat into the Earth’s oceans, ice caps, soils and atmosphere.
This rate of heat flow has doubled from the levels seen in the 1970s and 1980s to 0.96W/m2 measured over 2011 to 2023. This means nearly 1W/m2 of additional heat is flowing into every square metre of the Earth surface, 24 hours a day, 365 days per year.
Human-caused global warming has also increased by 0.1C in the four-year gap in tracking since the last IPCC report.
Remaining carbon budget
Our publication also reassesses the remaining carbon budget – the amount of CO2 that can be emitted while still keeping global warming below a certain level.
In 2020, the remaining carbon budget for a 50% likelihood of staying below 1.5C was around 500GtCO2, with an uncertainty range of 300-900GtCO2. At current emissions rates, that would be exhausted within around 12 years.
Since then, CO2 emissions and global warming have continued. At the start of this year, the same budget stood at 200GtCO2, with a range of 100-450GtCO2. This would be blown within less than five years at current rates.
The remaining carbon budget is also impacted by future non-CO2 emissions such as methane, as well as the cooling effects of aerosols such as sulphates. With non-CO2 emissions expected to contribute to warming going forward, the carbon budget also accounts for their predicted warming effect.
In this future scenario, we also assume methane and nitrous oxide emissions decline; if they do not, the carbon budget will be even smaller.
Record warmth in 2023
Last year saw a large increase in global temperatures, approaching 1.5C above pre-industrial levels in some datasets and reaching 1.43C in the average of four datasets used in the IPCC report.
Seeing 1.5C total warming during one year – or even more than one – does not mean that the Paris Agreement has been breached, nor does reaching or exceeding 1.5C warming in a particular month or location.
The Paris Agreement’s long-term temperature goal reflects global, human-caused, long-term temperature change that excludes short-term natural variability in the climate system. However, higher and rising annual temperatures clearly mean that we are heading in the wrong direction.
Our indicators show that, for the 2014-23 decade, observed global warming was 1.19C, of which 1.19C – that is, 100% – was caused by human emissions.
This is shown in the chart below, which compares the estimated human contribution to warming in individual years (grey) with assessments for 2023 (red), the trend in 2023 (blue) and the 2014-23 decadal average (green).
For the individual year of 2023, humans were responsible for 1.31C of the 1.43C that was recorded globally. This means that there was a substantial contribution from other causes to the record temperatures of 2023.
Contributing factors
The reasons for the record warm 2023 are still being investigated – for example, they could include shipping emission reductions (see below) as well as natural factors, such as the climate phenomenon El Niño.
Sometimes these factors are not easily distinguished as human or natural. For example, growing forest fires and their impact on emissions and the climate system.
Last year, Canada experienced its most severe fire season of the modern era, while there were also catastrophic fires in Hawaii, the Mediterranean, central Amazonia and central Chile.
Establishing how much of this biomass burning, the resulting emissions of aerosols and their effect on the climate is from natural wildfires is not easy.
For example, if the wildfires were caused by higher temperatures, themselves caused by human activity, this would be a climate feedback rather than from direct human activity.
This is an area where development of a consistent approach across datasets is needed. The same goes for methane, where emissions are primarily from fossil fuel production, agriculture and waste. Yet, emissions are also increasing from tropical wetlands under a warming climate.
There has been a lot of interest in how sulphur regulations from shipping led to a rapid fall in sulphur dioxide emissions in 2020 and possibly contributed to high global temperatures in 2023.
Our paper makes a preliminary investigation of its climate impact and we find that the global radiative forcing effect of the declining emissions would likely only have had a minor role in the high 2023 global temperatures.
We estimate that, globally, the cooling effect of the aerosols from the fires in Canada likely dominated any warming effect from shipping emission regulation changes.
Next steps
As 2024 unfolds, we hope that the indicators can shed further light on how human activity is shaping our climate at rates and levels not previously seen.
The aim is that they help lay the groundwork for the level of ambition needed for the latest national pledges under the Paris Agreement – the 2035 nationally determined contribution (NDC) commitments – where we expect countries to put more ambitious targets forward to the UN Framework Convention on Climate Change (UNFCCC) by 2025.
Perhaps our next update, which will be delivered to the Bonn negotiations in 2025, will begin to track a change in direction for the climate system that reflects a realisation of stronger and ambitious climate action for the longer-term.
The post Guest post: Tracking the unprecedented impact of humans on the climate appeared first on Carbon Brief.
Guest post: Tracking the unprecedented impact of humans on the climate
SYDNEY, Thursday 30 October 2026 — In response to reports that the Albanese government is set to introduce draft legislation this year that would seek to ban data centres in Australia’s suburbs, Joe Rafalowicz, Head of Climate and Energy at Greenpeace Australia Pacific, said:
“These reports are a testament to the growing community opposition to these completely inappropriate AI factories that have sprung up across our suburbs, and Big Tech corporations should take heed — the data centre build-out must not happen without the endorsement of the Australian people.
“But the government can’t simply ship this problem out to regional Australia without addressing the fundamental issues with this extractive new industry.
“We’re already seeing a trend of AI data centre proposals moving to the regions, in areas that are more water-scarce, more environmentally sensitive, and next to sources of fracked and coal seam gas to support their massive BYO gas-fired power plans — a pattern we’ve seen play out in the United States.
“From the Beetaloo Basin in the NT to the Western Downs in Qld, we’re seeing a wave of AI data centre proposals that would see new gas fast-tracked to support their massive energy demand, and threaten to completely derail Australia’s energy transition.
“Just as suburban Australians are asking, “what for?”, regional communities like Berry Springs and Dalby do not want dirty data centres setting up shop with absolutely no benefit to their communities. Greenpeace is calling for a moratorium on AI data centre developments until strict and enforceable safeguards are in place to protect our climate and our communities.”
-ENDS-
Media contact
Kate O’Callaghan on +61 406 231 892 or kate.ocallaghan@greenpeace.org
AI data centre ban in suburbs would not address fundamental issues: Greenpeace
In the thick of the COP29 climate summit in Azerbaijan in 2024, the UN climate talks were rattled by what can only be described as a major PR disaster. The BBC, Reuters and The Guardian all carried headlines, attributed to leading climate policy experts, that the COPs were “no longer fit for purpose”.
The articles outlined a series of reforms called for in an open letter signed by 22 eminent scientists and politicians, including a former UN secretary-general and previous UN climate chief, with a further 150 lending their support. The headlines shook confidence in the COP process, just as governments were wrestling over a new climate finance goal.
The Club of Rome – which handled the media relations for the letter – hurried to say that its “constructive, supportive ideas” had been “misinterpreted”. Negotiators kept calm(ish) and carried on, in the end landing the finance goal after some high-stakes drama on the final day.
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Early speakers’ list suggests few powerful leaders will attend COP31
Just 77 heads of state or government are scheduled to address the COP31 climate summit in Antalya, a third less than the COP28 peak -
Africa wants adaptation finance on COP31 agenda, raising risk of a fight
The African Group wants dedicated space on tripling adaptation finance, the Green Climate Fund and trade, setting up a possible clash
To my surprise, when I went back this week to read the letter again, I could not find the offending line about the COPs not being fit for purpose. The Club of Rome has yet to respond to my query about its disappearance.
Whatever happened to the wording, that sentiment has been widely shared. COPs have ballooned in size while the importance of their outcomes seems to have diminished since the 2015 Paris Agreement (with the exception of the 2023 COP in Dubai where countries agreed to transition away from fossil fuels in energy systems).
The same on the surface
Two years on from those painful headlines in Baku, has anything changed for the better? You might be forgiven for thinking not. Official decisions are still made by consensus rather than the majority voting some have called for to stop blockers.
Tens of thousands of officials, activists and business execs still scurry around the halls to an ever-growing list of side events, roundtables and dialogues, while deals still come down to rows, all-nighters and jargon-filled texts adopted to rounds of applause.
But it would not be true to say that COPs have completely failed to respond to the very real need to translate the words of the Paris Agreement into action in the outside world.
Global warming is projected to be around 1.3C lower this century than it would have been if the world had not committed to tackle the climate crisis under that accord. Developing countries have a valued space at COPs in which their voices have equal weight in decision-making, unlike in many other international fora. And most importantly, perhaps, there has been a subtle shift, tipping the balance away from negotiating towards doing.
Brazil branded last year’s summit in Belém as the “COP of Implementation”, corralling the sprawling Action Agenda into six axes. This was a bid to impose some structure on the mushrooming efforts between governments, UN agencies, cities, businesses and civil society to set targets and spur faster results on their pet issues, from methane emissions to health and adaptation in conflict zones. COP30 alone saw the launch of 120 “plans to accelerate solutions”.
COP30 roadmaps off the cuff
Meanwhile, as the formal negotiations drew to a close, it was clear that consensus decision-making was evolving into something a little more improvised.
With only around half of all countries on board with the idea of a roadmap to transition away from fossil fuels, COP30 President André Corrêa do Lago announced his team would put one together over the coming year, along with another on how to meet a global goal to halt deforestation by 2030. Those roadmaps will be launched next week, presented and discussed at COP31, though it’s still unclear whether or how they’ll be incorporated into the formal negotiating agenda.
Some leading policy-makers don’t think that matters too much. Speaking to journalists before the Antalya summit, COP30 CEO Ana Toni and Dutch climate minister Stientje van Veldhoven said “coalitions of the willing” can move ahead without needing consensus from the COPs. This, they said, was evident this year at the first global conference on TAFF, co-chaired by van Veldhoven and attended by 60 countries.
“Consensus or no-consensus in the general COP doesn’t make a difference for the choices I have to make in my country to get my country to phase out fossil fuels,” said the Dutch minister. The Netherlands recently became one of the first to publish a national TAFF plan.
COP31 banks on flagship voluntary initiatives
This thinking has permeated the management and expected outcomes of this year’s COP too. Earlier this year, Türkiye, supported by international energy agencies, floated the idea of a voluntary goal to boost electrification to 35% of the world’s final energy consumption by 2035 – and this is now being touted as one of the main results to be expected from Antalya.
Türkiye is also championing a pledge on AI and climate, while co-host Australia is pushing to ease access to climate finance for least developed countries and small island states.
COP31 presidency announces AI pledge as UN climate chief says Big Tech ‘on thin ice’
None of these needs consensus. But with a political cover decision already in the works, as trailed by the COP presidents, they – and perhaps the fossil fuel roadmap – may find a home in the official text if language acceptable to most can be found, giving them them additional weight.
UNFCCC reform process in the shadows
Formal reform is underway too, if quietly. UN climate chief Simon Stiell is leading a review informed by ongoing consultations with a group of 15 well-respected climate policy experts, three of whom signed the open letter in 2024.
Among them is leading Swedish climate and sustainability scientist Johan Rockström who has strong ideas about how to make COPs function better, including a switch to majority voting. He told the same press briefing nothing stands in the way of this, because the rules of procedure for making decisions at COPs have never been formally agreed.
Still, to get away from the default setting of consensus would require agreement on a new system that may be impossible to achieve given the rise in bullying tactics by fossil fuel heavyweights.
Comment: The UN climate process was built for negotiation – now it must support implementation
The deliberations with the high-level policy gurus, as reflected in a summary of June’s session in Bonn, largely echo what’s already happening organically, calling for stronger partnerships and accountability both in and between the Action Agenda and negotiations. It doesn’t mention voting.
A general overview of the reform exercise says that “improving and optimizing the [UN climate] process over the medium to long term… will be critical to fostering trust, enhancing collaboration, and catalyzing increased ambition”.
In the short term, don’t hold your breath for anything concrete on reform at COP31 but watch for signs in what ends up dominating the headlines from Türkiye.
The post Editor’s Desk: COP reform is happening quietly, behind the headlines appeared first on Climate Home News.
Editor’s Desk: COP reform is happening quietly, behind the headlines