Ten years since the Paris Agreement: what do experts say has changed?

December 10, 2025

On 12 December 2015, something just short of miraculous happened. Almost all the countries in the world (195 of them) agreed that the business-as-usual practices were harmful and promised to work together to combat climate change by adopting a legally binding international treaty known as the Paris Agreement.

The main long-term goals of the Agreement were to guide all nations to:

• substantially reduce global greenhouse gas emissions to hold global temperature increase to well below 2°C above pre-industrial levels and pursue efforts to limit it to 1.5°C above pre-industrial levels, recognising that this would significantly reduce the risks and impacts of climate change;

• provide financing to developing countries to mitigate climate change, strengthen resilience and enhance abilities to adapt to climate impacts. (1)

Now, ten years on, has it been a success?

This blog recaps key global developments since the Paris Agreement, drawing on the views of experts across related fields. Expect phrases such as “notable progress, however” and “good news, but…”

From a 4-6°C prediction to the possibility of 2.6°

The key change can be found in the report written by Climate Central and World Weather Attribution. They analysed the 2015 Emissions Gap Report and 2024 Emissions Gap Report and concluded that:

“Projected warming this century has dropped from about 4°C in 2015 to 2.6°C today — if current emissions reduction pledges are fully implemented.”

In the world where every fraction of a degree matters, this represents a significant shift.

However, it is important to note that 2.6°C of warming would still lead to a dangerously hot planet in this century.

“The world now experiences an average of 11 more hot days per year with the additional 0.3°C of warming since 2015. In a 2.6°C world, that increases to 57 extra hot days per year compared to now; at 4°C, that rises to an additional 114 hot days per year.” (2)

Some experts predicted that the world was heading towards a 6°C world, where the number of hot days would be even greater.

Why does the number of hot days matter?

The World Health Organisation estimates approximately 489,000 heat-related deaths occur each year . (3) With unequal access to cooling and structural inequalities that amplify vulnerability, adaptation to heat remains notoriously challenging. (4)

We also cannot ignore the ‘if’ in these predictions. The gaps between rhetoric and implementation are well-known and in the case of climate, such delays can be deadly.

Jennifer Morgan, former German State Secretary expects the rising cost of climate-linked disasters to give fresh impetus to the Paris Agreement goals. She said: “We know just in Europe extreme weather events cost 43 billion euros per year … not acting on climate has a huge cost to the economy, and that’s beginning to resonate with leaders.”

2. Emissions are still going up, but five times slower

The Energy and Climate Intelligence Unit has found global growth in carbon emissions compared to the previous decade has slowed fivefold, from 1.7% to just 0.32% a year. (5)

As the global economy has grown, emissions intensity per dollar has fallen by just over a fifth (21%) (6)
Global energy consumption continues to grow, but according to Our World in Data this also seems to be slowing, averaging around 1% to 2% per year. (7)

Fossil fuel use also continues to grow. In 2024 we saw a record high consumption of fossil fuels.
Some people understandably ask whether we are actually transitioning to clean energy if we keep increasing our consumption of fossil fuels? (8)

Hannah Ritchie in her new book Clearing the Air explains: “Between 2010 and 2022, global electricity generation increased by 7,590 terawatt-hours (TWh). Renewables supplied more than half – 57% of that increase. The rest came from fossil fuels. In a world without renewables, fossil fuels would have made up almost all that new demand. If we hadn’t deployed more renewables, the world would be emitting between 2.1 and 3.6 billion tonnes more carbon dioxide every year. That’s more than the emissions of the EU or India.”

The share of global electricity generated from solar and wind power has more than tripled since 2015. Just last month, BBC reported that for the first time ever, renewable energy overtook coal as the world’s leading source of electricity. (9)

Kelly Levin of the Bezos Earth Fund summed up: “Clean energy investment is now outpacing fossil fuels and new technologies are taking off – proof that progress is possible when ambition and investment align.”

Fatih Birol of the International Energy Agency said:

“Renewables are moving faster than national governments can set targets for. This is mainly driven not just by efforts to lower emissions or boost energy security – it’s increasingly because renewables today offer the cheapest option to add new power plants in almost all countries around the world.” (10)

This allows developing countries to leapfrog the adoption of fossil fuels that the so-called ‘developed’ world needed for progress and economic growth, and go straight for energy expansion that is both clean and cheap. This did not seem like a realistic possibility a decade ago, so although the use of fossil fuels is going up for now, it’s impossible not to appreciate the scale of change in the energy sector since the Paris Agreement.

3. Carbon sinks are struggling more

There is no “good progress, but” phrase in the nature section. I am afraid it’s just bad news. The world’s carbon sinks, which are virtually free to humans, are losing their amazing ability to absorb carbon dioxide and cool our planet.

In 2025, World Resource Institute reported that world’s forest carbon sink has shrunk to its lowest point in at least two decades, due to fires and persistent deforestation and that:“Without urgent intervention, a continued decline in forests’ ability to absorb carbon could accelerate climate change, increase the frequency of deadly extreme weather events, and disrupt rainfall patterns that underpin water and food security.” (11)

The annual 10 New Insights in Climate Science Report 2025 (written by more than 70 scientists from 21 countries) highlighted that the ocean,“another vital sink for carbon and heat – is soaking up less carbon dioxide, while more frequent and intense marine heatwaves ravage ecosystems and coastal livelihoods.” (12)

It’s important that plans to rapidly reduce carbon emissions go hand in hand with protecting nature.

4. Courts now recognise climate action as a legal duty of States

2015 marked the landmark Urgenda case in the District Court in the Hague – the first time a court, anywhere in the world, ordered a government to take stronger climate action. (13)

Also in 2015, Asghar Leghari took the Pakistani government to court, demanding that it does more to protect the country from increasingly severe climate impacts, and won.

Since then, nearly 3,000 climate cases have been filed globally. One notable one is Verein KlimaSeniorinnen Schweiz and Others v. Switzerland 2024 – the European Court of Human Rights ruled that climate inaction by a government had violated human rights.

2025 has been the most important year for climate litigation to date as both the International Court of Justice (ICJ) and the Inter-American Court of Human Rights issued Advisory Opinions on Climate Change.

The ICJ has specifically referenced the Paris Agreement and the obligations of States.
The Paris Agreement encourages all parties to submit: “Ambitious, economy-wide emission reduction targets, covering all greenhouse gases, sectors and categories and aligned with limiting global warming to 1.5°C, as informed by the latest science, in the light of different national circumstances” (para. 224).

Nationally Determined Contributions (NDCs) outline each country’s actions and should be submitted every five years. However, previously, some States and many commentators had argued that NDCs are entirely discretionary. (14) This has been one the main criticisms of the Paris Agreement.

The Opinion is clear in that NDCs are not entirely discretionary and must satisfy certain standards – the States are under an obligation to exercise due diligence when preparing their NDCs, ensuring that, when taken together, are capable of achieving the 1.5°C temperature goal (para. 245).

The Court clarified that due diligence requires States parties “to use all the means at [their] disposal” with a view to fulfilling their international obligations.

Crucially, the Court concluded that“Inaction, or failure to act decisively, may constitute an internationally wrongful act – triggering consequences under the law of state responsibility.” (15)

Julian Aguon (the leading attorney in this case) said: “[This Advisory Opinion] .. didn’t just open the door to a new era and that era being one of climate accountability, but it swung it wide open.” (16)

The Inter-American Court of Human Rights’ historic Advisory Opinion on the Climate Emergency and Human Rights also clarified that the obligation of States to “prevent irreversible and massive harm to the climate system is imperative” and recognised the right to a healthy climate as a human right.

We know the court systems around the world are slow but with this backing of international courts, the Paris Agreement might have just found new “teeth” for enforcement and perhaps in the next 10 years we will see much more action on climate change from States and businesses.

5. More businesses are on board with setting targets

The State of the Corporate Transition 2025 report assessed 2,000 of the world’s highest-emitting public companies and found that most companies have now acknowledged climate change as a significant issue, have a policy commitment to take action, have set an emissions reduction target, and disclose their Scope 1 and 2 emissions. There are, however, big differences in progress across sectors. The electricity sector, for example, achieved emissions intensity reductions nearly five times greater than steel and cement. The oil and gas sector, the most crucial sector for climate, made the least progress. (17)

Automotive sector warrants a special mention as ten years ago, we had 1 in every 100 vehicles sold into the market being electric, and today we have 1 in 5. (18)

In other good news, 9,000+ companies across sectors have had their targets validated by the Science Based Targets initiative (SBTi), representing billions in revenue and millions of tonnes of emissions. (19)

However, there are claims that fewer than 1% of companies have committed to align capital expenditure with their decarbonisation goals. This indicates that companies are not clear on how emissions reduction targets will be financed. Some companies’ plans also depend on unproven technologies. (20)

Another damning statement comes from the State of Climate Action 2025 report from the World Resources Institute (WRI): “Across every single sector, climate action has failed to materialise at the pace and scale required to achieve the Paris Agreement’s temperature goal.” (21)

6. Final words

A recent publication in Ensured by Irina Kustova et al states that: “Global climate finance targets have been met on paper, but flows remain inadequate, delayed, and uncertain, eroding trust.” (22)
You will see words “inadequate”, “delayed” or “uncertain”, or synonyms thereof describing climate progress in many articles.

When asked if the Paris Agreement had failed, Christina Figueres, one of architects of the Paris Agreement, answered decisively:

“I wouldn’t say we have failed. I would say, actually, we’re not there yet. This is a new economy that is being built, that is being reconfigured, […], and no overarching economic structure can be changed from Sunday to Monday.

Ten years have shown that it is entirely possible to re-conceive, restructure, and redesign the economy, but they have not guaranteed yet that we can take all the sectors because this is still a new experience and new challenge that we have .. […] hence we have to redouble our efforts.” (23)

The global nature of the problem, the need for speed, and many political challenges, unsurprisingly, have made the implementation on the Paris Agreement extremely complicated, however, without a doubt, there has been much progress that can be built upon.

Lastly, it’s important to note that Paris Agreement was never designed to achieve its goals in 10 years. We will be working on this mission for many, many decades.. However challenging the setbacks have been, now is not the time to give up on Paris, but instead, as Christina said, “we have to redouble our efforts.”

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