Lecture "Cambio climático: ciencia, irreversibilidad y compromiso" (Climate change: science, irreversibility and compromise).

Speaker: 

J. Fidel González Rouco (Dept. of Earth Physics and Astrophysics & Institute of Geosciences, IGEO (UCM-CSIC))

Abstract:

The planet's global temperature has increased by about 1°C since the mid-19th century. The rise has been global. The highest values occur at high latitudes in the Northern Hemisphere, due to albedo decrease feedbacks, and are higher over the continents than over the ocean, by virtue of different thermodynamic properties. These changes are the result of one in the radiative balance on a planetary scale, and are also consistently detected in other variables indicative of the state of the system such as sea level, amount of glacier mass, stratospheric temperatures, etc.

Nowadays we know most of these changes are due to human activities and the changes will continue in the future with an intensity and speed which depends on future greenhouse gas emissions. We can understand this change as an irreversible process because carbon concentrations remain roughly stable in the atmosphere for centuries. 

Therefore, if limits are to be placed on temperature rise, the total amount of carbon emitted into the atmosphere must be limited too. There is a narrow range of emissions that can still be made if global temperature rise is to be limited to 1.5-2°C by the end of the 21st century. Limiting impacts to the level of a temperature increase of 1.5°C instead of 2°C is important and avoids serious and discernible consequences for ecosystems and society.

Limiting global temperature increase and related impacts on a regional scale contributes to the feasible development of the 2030 Agenda for Sustainable Development goals. From this point of view, it is useful to formulate the impacts of current and future climate change within the framework of human rights, including the right to water, food, health and development, among others.