Which greenhouse gas has a global warming potential of 265 over a 100-year time horizon?

The greenhouse gas that has a global warming potential (GWP) of 265 over a 100-year time horizon is nitrous oxide (N2O). The GWP is a measure that compares the impact of different greenhouse gases on global warming, taking into account how much energy each gas can trap in the atmosphere over a specified timeframe, typically 100 years.

Nitrous oxide is produced through agricultural and industrial activities, as well as during combustion of fossil fuels and solid waste. It has a strong radiative effect, meaning it is very effective at trapping heat in the atmosphere relative to carbon dioxide, which has a GWP of 1.

Understanding the GWP of different greenhouse gases is critical for climate change policy and discussions, as it helps in assessing the effectiveness of various mitigation strategies. By recognizing the significant impact of nitrous oxide, efforts can be prioritized to reduce its emissions, often through improved agricultural practices and the management of fertilizers.

In contrast, carbon dioxide is the most prevalent greenhouse gas with a GWP of 1, while methane has a GWP of about 28-36 over the same period. Nitrogen trifluoride (NF3) has a GWP that is significantly higher than nitrous oxide but is present in