In December 2015, the UN climate conference in Paris adopted Paris Agreement, an international climate change treaty. At the time, there was huge euphoria and an agreement in which almost all the countries of the world committed to reducing emissions to net zero by 2050 was seen as the end of fossil fuels.

The key objective of the agreement was to keep the increase in global average temperature well below 2°C above pre-industrial levels and to strive to limit the increase to 1.5 °C, a goal promoted by vulnerable countries as „1.5 for survival.“ The agreement focuses on climate change mitigation, adaptation, and financing.

The controversial reality of the first decade

Despite the ambitious goals, the reality of the past decade has been different. From an atmospheric perspective, the past decade has been a slow fever dream, during which pollution from fossil fuels has continued to increased year by year. Since the agreement was adopted, about 300 gigatons of carbon have been released into the atmosphere. These emissions have contributed to the amplification of climate disasters, from the massive hurricane that hit Puerto Rico in 2017 to the most powerful Atlantic storm on record, which hit Jamaica in October 2025.

The failure was also compounded by the fact that governments that had promised to reduce emissions continued to approve new fossil fuel projects. According to the report, global greenhouse gas emissions (excluding LULUCF) in 2024 would reach 53.2 Gt CO2eq, representing an increase of 1.3 % compared to 2023. The energy industry also bears significant responsibility, maintaining its position as the dominant sector with almost 30 % share of total emissions. Moreover, a study from March 2025 confirmed that half of the world's CO2 emissions from fossil fuels was caused by only 36 companies, confirming their disproportionate impact on the crisis.

Ironically, it was during this period that scientists discovered that they had underestimated some of the threats of climate change. For example, in 2025, it was announced that the Earth had crossed one of the first tipping points - much of the coral reefs would no longer be able to recover.

Political turbulence and the 1.5°C target

Climate diplomacy has also faced significant political challenges: The United States, the second-largest emitter of greenhouse gases, has seen several withdrawals and re-entry into the agreement. Donald Trump, who has publicly called climate change „the greatest hoax ever perpetrated,“ has canceled billions of dollars in clean energy projects. The US officially withdrew from the agreement in November 2020, rejoined in January 2021 under Joe Biden, but January 20, 2025 President Donald Trump has again signed an executive order withdrawing the US from the agreement.

These facts have led to the key goal of limiting global warming to 1.5°C is now almost certainly unattainable or has already been exceeded. The 2023 Global Stocktake confirmed that while the agreement has had a significant impact in reducing the worst-case warming scenario (from 3.7–4.8°C in 2010 to 1.7–2.1°C under long-term commitments), the world is still far from the 1.5°C target.

Light at the end of the tunnel: Renewables and growing ambitions

Despite the obstacles, there are reasons for optimism. The huge positives include rapid development of renewable energy sources. In the first half of 2025, renewables overtook coal for the first time as the world's main source of energy. Wind and solar are expected to meet 90 % of new electricity demand this year. Solar power installations are happening up to fifteen times faster than predicted in 2015.

Moreover, it is evident strong public support: a 2024 survey showed that 89 % of the world's population favors stronger political action on climate change.

From a political perspective, a key shift occurred in 2023 when world leaders at the COP conference in Dubai for the first time, they added language to the Paris Agreement calling for a shift away from fossil fuels.

The European Union submitted an updated Nationally Determined Contribution (NDC) ahead of COP30, confirming its target of reducing greenhouse gas emissions by 55 % by 2030 (compared to 1990) and aiming to 90 % emissions reductions by 2040, with a plan to achieve carbon neutrality by 2050.

NDCs and the upcoming COP30

The Paris Agreement is based on Nationally Determined Contributions (NDCs). These are voluntary targets that countries set themselves, but with an obligation to submit and maintain progressive targets that should be more ambitious than the previous one (principle of „progression“). Although NDCs are not legally binding, the reporting and review procedures are.

Although economic trends suggest that the transition to clean energy is inevitable, the question remains whether it will be fast enough and fair enough. The next important step in the international process will be the Congress COP30 in Brazil. The mood of urgency and optimism that prevailed in Paris a decade ago should not be forgotten. JRi