Anthropogenic climate change is caused by greenhouse gas (GHG) emissions and by land use changes, which greatly alter the atmosphere and consequently also alter the climate patterns; it is urgent to fight these changes.

Why mitigation?

Mitigation consists of reducing the emissions of GHG to the atmosphere. With the aim of preventing the most severe risks of climate change, particularly those that are irreversible, the countries that signed the Paris Agreement in 2015 compromised to limit global warming to well below 2 °C compared to pre-industrial levels, and to develop efforts to keep that warming to 1.5 °C. The current GHG emission trends show that reaching these goals is gradually becoming more difficult. There is not much room for maneuver left and emissions need to be drastically reduced in the next decades.

Isn’t reducing emissions enough?

Let’s consider the most optimistic scenario, in which GHG emissions are substantially reduced worldwide, reaching carbon neutrality (balance between carbon dioxide emissions and their absorption; also known as “net zero” carbon). Ideally, there will also be a drastic reduction in the emission of other GHG, such as methane and nitrous oxide.

Even in this ideal situation of reduction in GHG emissions, we must not forget that the atmosphere is an extremely complex system and changes do not take effect immediately. In fact, regardless of the emission reduction that occurs from now on, changes caused by past emissions will still be felt for a very long time. For example, temperatures will continue to increase until the middle of the century, and the effects on oceans and sea level rise are irreversible in the next centuries or even millennia.

What is the purpose of adaptation?

Climate change adaptation emerged as a way to deal with the effects of unavoidable extreme climate events and their environmental, social and economic impacts. Through adaptation, it is possible to reduce or avoid damage, and at the same time take advantage of the beneficial opportunities caused by climate change.

When preventive measures are taken, it is possible to avoid many costs. Here are two examples:

• A research by Feyen and Watkiss in 2011 showed that a 1 € investment in adaptation measures to prevent flooding can save an average of 6 € in damage costs;
• Another study by Pappenberger et al in 2015 showed that investing in early warning systems can bring benefits of around 400 € for each 1 € invested.