Thread: Any doubts about Climate Change?

Zeke Hausfather @hausfath.bsky.social

Here are monthly temperatures in ERA5 along with the projection (and two-sigma uncertainty) for April:

@hausfath.bsky.social on Bluesky

Carbon Brief @carbonbrief.org
NEW – State of the climate: 2025 close behind 2024 as the hottest start to a year |
@hausfath.bsky.social

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NASA – March 2025 was the 2^nd warmest March recorded.

NASA

Fossil fuel companies caused $28 trillion in climate damage, study finds. These 5 are tied to the most harm.

Extreme heat caused by emissions from 111 fossil fuel companies cost an estimated $28 trillion between 1991 and 2020, according to researchers at Dartmouth College.

Their study, which was published Wednesday in "Nature," presents a peer-reviewed method for tying emissions to specific climate harms. Their goal is to help hold companies liable for the cost of extreme weather, similar to holding the tobacco industry liable for lung cancer cases or pharmaceutical companies liable for the opioid crisis.

The research firm Zero Carbon Analytics counts 68 lawsuits filed globally about climate change damage, with more than half of them in the United States.

"We argue that the scientific case for climate liability is closed," wrote the study's authors, Christopher Callahan, who received his PhD from Dartmouth College, and Justin Mankin, a Dartmouth Department of Geography professor.

5 top emitting companies

About a third of the total cost was attributed to five companies, which can be tied to more than $9 trillion in climate damage, according to the study.

These are the top-emitting companies:

• Saudi Aramco: $2.05  trillion
• Gazprom: $2  trillion
• Chevron: $1.98  trillion
• ExxonMobil: $1.91 trillion
• BP: $1.45  trillion

https://www.nature.com/articles/s41586-025-08751-3.epdf

5 ways we’re making progress on climate change

Any time I try to convince skeptical people that the world isn’t as bad as they think it is — which I do quite a lot, given that I write a newsletter called Good News — they usually come back with a two-word rejoinder: “climate change.”

It’s a tough one to rebut. Climate change is very real, and its toll is worsening by the year. 2024 was the hottest year on record, and the first year where the average global temperature was 1.5 degrees Celsius higher than it was in the pre-industrial era — a red line set by policymakers as part of the Paris agreement. Antarctica’s winter sea ice dropped to its second-lowest level on record this past fall, while the world has now experienced more than $4 trillion — yes, with a “t” — in damages from extreme weather events since 1970. And in the White House, President Donald Trump is busy eviscerating government climate research and pulling back on clean energy policies.

Climate change presents a difficult challenge to the narrative of progress. Not just because it’s causing death and destruction now, and not just because each year it gets cumulatively worse, but because in many ways it is the direct result of trends that have otherwise made the world better.

Economic growth makes us all better, but it requires more energy, and as long as that energy mostly derives from fossil fuels, which still provide about 80 percent of global energy, it will make the world warmer as well. In a particularly bitter irony, one of the most important environmental advances in recent years — the reduction in conventional air pollution — seems to play a role in accelerating the pace of climate change.

But two things can be true: Even as climate change gets worse every year, every year we’re making more progress to slow it down. That’s the theme of “Escape Velocity,” an excellent package that came out this week from Vox’s climate team. As Vox climate editor Paige Vega wrote: “The energy economy is transitioning. Technology is advancing. The market is shifting. Our politics might feel stuck, but in many important ways, we continue to move forward.”

So, in honor of the end of Earth Week, here are five positive trends that demonstrate that the fight against climate change is far from lost.

1. The worst-case scenario is looking better

Climate change is bad now, but it could do even more damage in the future, as the carbon dioxide we’re adding to the atmosphere keeps accumulating. The worst-case scenario outlined by UN climate scientists could result in as much as 4° to 5°C of warming, which could reduce global GDP by as much as 15 percent, destroy coral reefs around the world, leave large parts of the Earth all but uninhabitable, and push the world past environmental tipping points with consequences we can’t begin to know.

2. Clean energy is beating coal
3. Batteries are world-beating
4. The clean-energy economy is humming
5. Climate innovation is only getting started

https://www.yahoo.com/news/5-ways-ma...123000252.html

Zack Labe @zacklabe.com
For March 2025, sea surface temperatures across the northern half of the Atlantic Ocean were below the recent exceptional peak, but still record high compared to all other years in this dataset. Data from psl.noaa.gov/data/gridded...

@zacklabe.com on Bluesky

Zack Labe @zacklabe.com

The global mean surface air temperature anomaly (departure from average) so far this year compared to the last 150+ years... Data from NOAAGlobalTemp v6.0.0 averaged over January to March and available from www.ncei.noaa.gov/products/lan...

@zacklabe.com on Bluesky

JMA – March 2025 was the 3^rd warmest March recorded

Five Warmest Years (Anomalies)

1st. 2024(+0.66°C), 2nd. 2016(+0.57°C), 3rd. 2025(+0.56°C), 4th. 2020(+0.50°C), 5th. 2023(+0.49°C)

JMA

Gavin Schmidt @climateofgavin.bsky.social

Annual update of the Nenana Ice Challenge timeseries. Trend since 1970 is an earlier date by about 1.3 days per decade.

(break up date via @alaskawx.bsky.social): @climateofgavin.bsky.social on Bluesky

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Canadians chose Mark Carney who leads the ruling Liberal Party, as their prime minister in MondayÂ’s election, rejecting the anti-climate action Conservative Party of Pierre Poilievre.

Carbon tax on industry stays

But he did maintain the carbon price on big industries, which the Conservatives had promised to scrap. Analysis from the Canadian Climate Institute suggested that, while the consumer carbon price grabbed the headlines, the industrial price was expected to drive three times more emissions reductions by 2030.

CarneyÂ’s election manifesto also promises to boost electric vehicle production and use, as well as infrastructure to transmit electricity across the country and carbon removal and storage technology.

The Conservative manifesto pledged to “unleash Canadian resources”, by scrapping the emissions cap on oil and gas production, enabling construction of gas export terminals on Canada’s west coast and approving oil exports from Arctic ports.

China Briefing 1 May 2025: Xi steadfast on climate; Solar and wind surpassed thermal power; Controlling short-term GHGs

China confirms climate commitment

XI’S NOT FOR TURNING: Chinese president Xi Jinping confirmed that the country’s 2035 “nationally determined contribution” (NDC) will cover the “entire scope of the economy, including all greenhouse gases” and be published before COP30, Bloomberg reported. It added that these comments, made at a virtual meeting of global leaders, signaled that “China won’t back off from its ambitions” on climate change, despite economic and geopolitical challenges. Reuters noted that Xi also flagged that “China’s actions to address climate change will not slow down”. As “Xi’s first international appearance on climate change since 2021”, the speech “sends a clear signal of China’s support for multilateralism”, Li Shuo, director of the China Climate Hub at the Asia Society Policy Institute, told Bloomberg. Nevertheless, campaign group Greenpeace East Asia global policy advisor Yao Zhe “cautioned against” interpreting it as meaning that an ambitious climate pledge is “guaranteed”, Climate Home News said, adding that it “remains an open question, especially given the ongoing tariff war with the US”.

BRAZIL’S INFLUENCE: The meeting was part of a broader campaign by COP30 host Brazil to persuade China, the EU and other powers “to commit to cutting greenhouse gas emissions enough to keep global warming well below 2C”, Reuters reported. Shortly before the meeting, Huang Runqiu, head of China’s Ministry of Ecology and Environment, reaffirmed China’s commitment to tackle climate change at a meeting with COP30 president André Corrêa do Lago in Beijing, according to China Environment News. Corrêa do Lago later told journalists he believes China is developing a “very ambitious” climate pledge, Bloomberg said.

Short-term pollutant

HFCs are man-made GHGs that can be several thousand times stronger at absorbing heat than carbon dioxide (CO2). One type, HFC-23, is 10,000 times more powerful than CO2.

They are used in a number of appliances, particularly as coolants for fridges and air conditioning.

Efforts to phase them out are governed by the 2016 Kigali Amendment to the Montreal Protocol on ozone-depleting substances, which China ratified in 2021.

China is the world’s largest producer and consumer of HFCs, accounting for more than 70% of global production and 50% of consumption. It also produces and consumes the majority of the appliances that use them.

Its HFC emissions stood at 273m tonnes of CO2 equivalent (MtCO2e) in 2020, according to the government’s recently-submitted GHG inventory. This is equivalent to more than 2% of China’s CO2 emissions that year, which totalled 11bn tonnes.

Despite HFCs’ relatively low share in overall GHG emissions, their absorption strength necessitates their inclusion in climate strategies, says Sun Xiaopu, senior China counsel at the thinktank Institute For Governance and Sustainable Development (IGSD).

She told Carbon Brief that mitigating HFCs will help avoid “short-term global warming” and climate tipping points.
Action plan for 2030

The government’s plan sets targets and timelines for “gradually reducing” production and consumption of appliances using HFCs by 2030, as well as reducing or banning consumption of ozone-depleting substances (ODSs).

These include lowering HFC production by 2029 by 10% from a 2024 baseline of 2bn tonnes of CO2 equivalent (GtCO2e). Consumption would also be reduced 10% from a baseline of 900MtCO2e in this timeframe. This aligns with China’s obligations under the Kigali Amendment.

From 2026, China will “prohibit” the production of fridges and freezers using HFC refrigerants.

From 2029, it will ban the use of HFCs in most cooling systems, including air conditioners and other refrigeration equipment – prioritising the automotive, home appliance and industrial cooling sectors.

To enforce this, China will take measures such as requiring licences for manufacturing and consumption of controlled HFCs, improving monitoring of the production of HFC-23, as well as encouraging recycling of HFC refrigerants, and imposing import and export quotas for HFC refrigerants (although not the appliances that use them).

The plan will also introduce “stricter legal liabilities and higher financial penalties” to deter non-compliance, said Zheng Tan, programme officer of the industry programme at the climate nonprofit Energy Foundation.

He told Carbon Brief this is a “crucial step” in strengthening China’s existing HFC policy framework.

https://www.carbonbrief.org/china-br...ort-term-ghgs/

Zeke Hausfather @hausfath.bsky.social

April 2025 was the second warmest April on record (after 2024) in the ERA5 dataset, at around 1.51C above preindustrial levels: @hausfath.bsky.social on Bluesky

Canada Rebukes Trump—But That May Just Be the Start of Mark Carney's Role in History

I’ve been watching Carney for a long time and there's a few things you should know about this man, especially as the U.S. president tries to drag the world back onto the dead-end street of fossil fuels.

I want to tell you today about two potential bright spots.

The most obvious joy, of course, came last night in Canada, where citizens of the not-51st-state rejected a Trump-lite figure named Pierre Poilievre (who had been leading by 23 points on January 20!) and instead elected Mark Carney to lead their country. This has been correctly interpreted by all as a reaction to the ham-handed bullying of the canned ham currently resident in the White House. But though he was elected a little by accident (albeit after a brilliant campaign) it means something far more: in Carney we now have the world leader who knows more than any of his peers about climate change. And who knows roughly twenty times as much about climate and energy economics as anyone else in power. He may turn out to be a truly crucial figure in the fight to turn the climate tide.

Highlight

A year later, wearing a tux and speaking at an opulent dinner to the “names” who run the premier insurance brokerage Lloyds of London, Carney went further, giving one of the most important speeches of the climate era. It is well worth reading in its entirety, but here is the crucial section

Climate change is the Tragedy of the Horizon.

We don’t need an army of actuaries to tell us that the catastrophic impacts of climate change will be felt beyond the traditional horizons of most actors – imposing a cost on future generations that the current generation has no direct incentive to fix.

That means beyond: - the business cycle; - the political cycle; and - the horizon of technocratic authorities, like central banks, who are bound by their mandates.

The horizon for monetary policy extends out to 2-3 years. For financial stability it is a bit longer, but typically only to the outer boundaries of the credit cycle – about a decade.

In other words, once climate change becomes a defining issue for financial stability, it may already be too late.

And so, as Politico put it, Joyce received a “shrug.”

Joyce’s speech was met with silence. The “awkward but unanimous” moment was “telling,” said one European official who was in the room.

Responding to Joyce’s comments, U.K. Energy Secretary Ed Miliband told POLITICO: “I think overall, I would say that the general tenor of these discussions indicates where people are going, which is toward a clean energy transition.”

Full article: Canada Rebukes Trump—But That May Just Be the Start of Mark Carney's Role in History

Zeke Hausfather @hausfath.bsky.social

With the first four months of the year now available, I estimate that 2025 is most likely to be the second warmest year on record at 1.52C in ERA5, with a ~8% chance of beating 2024 as the warmest and a ~25% chance of coming in at the third warmest after 2023: @hausfath.bsky.social on Bluesky