What are greenhouse gases?

A new United Nations report has warned that global temperatures could continue to rise even under the most optimistic climate scenarios. According to the report, the world’s average temperature could reach 1.7°C to 1.8°C above pre industrial levels by the middle of this century.

The report, released on Wednesday by the United Nations Environment Programme (UNEP) stresses that countries must make major cuts in greenhouse gas emissions to slow global warming and reduce its harmful effects.

What are greenhouse gases?

Greenhouse gases are gases in the atmosphere that trap heat and prevent some of it from escaping into space. These gases are necessary to keep Earth warm enough for life.

However when their levels become too high they cause global temperatures to rise.

Human activities particularly the burning of fossil fuels are increasing the amount of these gases in the atmosphere and contributing to climate change.

How much must greenhouse gas emissions fall?

The UNEP report says the world needs to reduce greenhouse gas emissions much faster to limit future temperature increases.

According to the report, global emissions must fall compared with 2025 levels by:

•18% by 2030

•45% by 2035

•69% by 2040

However current national climate plans are not strong enough to meet these targets. Under existing commitments emissions are expected to fall by only 5% to 8% by 2030 and 11% to 15% by 2035.

This gap highlights the need for stronger climate policies and faster action by governments worldwide.

Global temperatures could rise by 2.8°C by 2100

The report warns that if current climate policies remain unchanged, global temperatures could rise by as much as 2.8°C above pre industrial levels by the end of the century.

Even if countries fully meet their existing climate commitments temperatures could still increase by around 2.6°C.

Both estimates are higher than those presented in last year’s report. The UNEP identified several factors behind the revised projections including the United States withdrawal from the Paris climate agreement and changes to earlier estimates of greenhouse gas emissions.

UN Chief calls for continued climate action

As preparations continue for the upcoming COP31 climate conference in Türkiye, United Nations Secretary General António Guterres has stressed the importance of continuing efforts to tackle global warming.

Rising temperatures are increasing the risks associated with extreme weather events including floods and wildfires. Experts warn that further warming could make these events more severe and create additional challenges for communities around the world.

The UN chief’s message is that countries must not abandon their efforts to limit global warming, even as the climate challenge becomes more difficult.

Is the 1.5°C Climate target still possible?

Under the 2015 Paris Agreement countries agreed to keep global warming well below 2°C and make efforts to limit it to 1.5°C above pre-industrial levels.

However the latest UNEP report suggests that staying within the 1.5°C limit has become increasingly difficult.

According to the report there is only about a 50% chance that global temperatures will return to the 1.5°C level by 2100. It also states that climate plans announced since the previous report have made little difference to long term temperature projections.

Can carbon removal help reduce global warming?

The report suggests that bringing global temperatures back down to the 1.5°C level would depend heavily on removing large amounts of carbon dioxide from the atmosphere.

Carbon removal involves capturing carbon dioxide from the air and storing it so that it does not continue to contribute to global warming.

However there is still considerable uncertainty about whether these methods can be used on the scale required.  Reducing greenhouse gas emissions remains essential to limiting future temperature increases.

Final thoughts

The latest UNEP report highlights the growing gap between the world’s climate goals and the action being taken to achieve them. Without deeper cuts in greenhouse gas emissions global temperatures could rise well beyond the limits agreed under the Paris climate agreement.