It is worth noting that climate change has been a feature of Earth throughout its history, and this will continue to be the case in future. The climate is affected by numerous factors that each function on different timescales: continental drift (a timescale of millions of years), the Earth’s orbital parameters (e.g. the radius of the Earth’s orbit around the sun, a timescale of 100,000 years), and the intensity of solar radiation itself (the eleven-year sunspot cycle). The climate is also influenced by interactions between the different components of the climate system, such as the atmosphere, the oceans, the biosphere, the cryosphere, and land surfaces.
Ever since industrial societies emerged, humans have been actively changing the climate by altering landscapes and influencing the composition of the atmosphere. Carbon dioxide (CO2) plays a particularly big role in anthropogenic climate change. The atmospheric concentration of carbon dioxide has risen significantly since the industrialisation of the mid-19th century, growing from around 280 ppmv to almost 400 ppmv.
The impact on the climate is, much like the climate system itself, highly complex. One clear sign of the effects is that the global average temperature rose by about 0.85°C between 1880 and 2012. The way the climate develops in future will depend very heavily on what happens with the concentrations of greenhouse gases in the atmosphere. The consequences of climate change are many and diverse. It can cause an increase in droughts in already arid regions, and lead to rising sea levels. Countries can only prepare themselves if they undertake enormous efforts in areas such as agriculture, urban planning, transport, and coastal protection. Richer countries can afford to combat the effects of climate change by implementing adaptation and protection measures. However, climate change has a global impact, with direct and indirect regional consequences.
Poorer countries and densely populated countries located in large delta regions or coastal regions, such as those in Africa and Asia, must rely on outside help because they will struggle to master the effects of climate change alone. This is a shared global challenge that is to be shaped into a binding, post-Kyoto agreement at the UN climate talks in Paris in autumn 2015.
This question was answered by Dr Klaus Grosfeld, Managing Director of the Helmholtz Climate Initiative REKLIM (Regional climate change).