A new one scientific study shows that a collapse of the Gulf Stream could happen as early as 10 to 20 years as a result of global warming. This would mean a significantly changed and colder climate in Denmark, while the southern hemisphere would experience far more and more intense heat waves and droughts. If this happens, it would have major consequences for Danish agriculture and require us to think about food production in a completely new way. Therefore, climate action that has a significant effect on global warming in the short term is more important than ever.

Methane makes the biggest difference here and now

Everyone knows that we need to reduce emissions of climate-damaging greenhouse gases, but few know that reductions in the greenhouse gas methane have a much greater effect on global warming than CO.₂ – especially in the short term.

In 20 years, one ton of methane warms the planet over 80 times more than one ton of CO₂. Over 100 years, it is about 30 times more. The difference is because methane only stays in the atmosphere for 12-15 years. This means that methane reductions today will be felt already this decade.

At a time when global temperatures have already risen by 1,1 degrees since industrialisation, and 2024 was the warmest year on record with a global temperature rise of 1,6 degrees, we cannot afford to wait for long-term results. In the EU alone, climate change is already estimated to have cost over 300 billion kroner this year – an amount expected to triple by 2029.

Focus must be on the next decades

When Denmark calculates its climate footprint and the effect of climate policy decisions, the different warming effects of greenhouse gases are converted to the common standard CO₂-equivalents (CO₂e) – so how many tons of CO₂ one ton of a given greenhouse gas, such as methane, corresponds to.

Since the Kyoto Protocol was adopted in 1992, has the vast majority of climate models — including those used as the scientific basis for international agreements such as the Paris Agreement — converted methane to CO₂e based on the global warming potential over 100 years (GWP100)The 100-year perspective as a standard is today in many ways outdated, because today we are faced with imminent climate goals that must be met, and not least temperature increases that can cause irreversible climate change.

If we instead used figures for the effect of greenhouse gases on global warming over a 20-year period (GWP20), it would become quite clear what a significant effect methane has on global warming in the coming decades.

GWP100, on which all political decisions and calculations are based, therefore underplays the significant role that methane reductions have in limiting temperature increases in this decade. Decision-makers should therefore also include the short-term perspective (GWP20) in the future to clarify which decisions will have a faster effect on global warming.

Agriculture is the primary emitter

The primary sources of methane emissions globally are the energy, waste and agricultural sectors. In Denmark, around 80 percent of emissions come from agriculture, of which approximately 57 percent of emissions come from the digestive process in ruminants (especially cows), and 43 percent come from livestock manure.

The Green Tripartite can with CO₂The tax and land set-aside will be an important step towards greener agriculture, which can also inspire other countries to transform their food production. But if Denmark is to truly be the green pioneer that we pride ourselves on being, it will require that the transformation of agriculture towards a more plant-based agriculture be accelerated. This will require further initiatives that affect both the production and consumption sides.

There are many steps on the way to ensuring the necessary methane reductions to reduce global warming, avoid major climate damage and reduce climate effects on Danish agriculture.

The first step is simple: Put methane on the agenda, calculate the effect on global warming in the short term, and include it in the basis of our climate policy. The next step requires more – but it is both necessary and possible. To act consistently on it with a clear plan that shows how Denmark will significantly reduce its methane emissions.

Methane reductions are not the whole solution, but they are one of the fastest ways to slow warming. That is why methane needs to be brought to light and not hidden in calculation models.

This debate post was written by Lærke Kjærbye-Thygesen, advisor to the Green Transition Denmark, and Martin Benny Pedersen, junior consultant to the Green Transition Denmark, and has been brought into Climate monitor on October 29, 2025.

Photo: Frederik Sørensen, pexels.com