How the climate could change in the Arctic and South Asia

A climate scenario is a description of possible future climate development, in meteorological terms. SMHI's climate scenarios are now available for two new areas; the Arctic and South Asia.

The climate scenarios are generated within the framework of Cordex, which aims to provide high-resolution scenarios for all of the land areas on earth.

Skärmklipp - klimatscenario Arktis eng
Calculated change in annual mean temperature (°C) for the period 2071-2100 compared with 1971-2000. The map is based on an ensemble with four climate scenarios for the RCP8.5 scenario. Enlarge Image

"Future climate change is estimated using climate models. A climate model is a computer program that describes the physical laws that we know control the climate system. The estimations are made using powerful supercomputers. Climate models are supplied with assumptions about future levels of greenhouse gases, to see how they might affect the climate of the future," says Gustav Strandberg, a researcher at SMHI.

The climate scenarios for the Arctic and South Asia are freely available on

"There are two scenarios for the respective areas, one that is based on continually high emissions of greenhouse gases, and one where emissions are limited. On the maps users can see how temperature and rainfall can change depending on the different emission levels," explains Lena Lindström, Product Manager for Climate Services at SMHI.

The climate in the Arctic affects northern Europe

Climate change is not evenly distributed over the earth, and changes are very different in different areas.

"The Arctic is the area where the temperature change is expected to be the highest; higher for example than in Europe. That is why it is important to keep an eye on the region. Not least because the climate in the Arctic affects the climate in Northern Europe," says Gustav Strandberg.

Multiple model runs are necessary

When SMHI generates regional climate scenarios like these they are based on regional climate models, which in turn are based on different global climate models.

"The scenario service for Asia is based on a combination, or ensemble, of ten different climate model runs and two different scenarios. Four different climate model runs were used for the Arctic. The ensemble gives a good overview of the spread between the different climate scenarios and highlights some of the uncertainties associated with simulating the future climate. The ensembles provide a measure of the reliability of results. If several climate model runs give similar results it increases the relative reliability compared to if they all point in different directions," explains Gustav Strandberg.

Information is needed for the whole world

The need for regional climate information is great. Within Cordex, researchers collaborate across borders, so there are opportunities to generate detailed climate scenarios, even for areas that do not produce the basic material themselves. This is particularly important for developing countries. SMHI has already generated climate scenarios for Africa and Europe. Between 17 and 20 May, 350 climate researchers are gathering at the international Cordex conference in Stockholm to share their experience and determine further work.