Last week the World Bank issued a powerful report with the title Turn Down the Heat: Why a 4°C warmer world must be avoided.
The well-referenced 70 page report is intended, according to Dr. Jim Yong Kim, President of the World Bank Group, to shock the world into action. It spells out what the world would be like if it warmed by 4 degrees Celsius, which is what scientists are nearly unanimously predicting by the end of the century, without serious policy changes.
The report states that the 4°C scenarios are devastating:
- the inundation of coastal cities;
- increasing risks for food production potentially leading to higher malnutrition rates;
- many dry regions becoming dryer, wet regions wetter;
- unprecedented heat waves in many regions, especially in the tropics;
- substantially exacerbated water scarcity in many regions;
- increased frequency of high-intensity tropical cyclones; and
- irreversible loss of biodiversity, including coral reef systems.
The report states that a 4°C world will pose unprecedented challenges to humanity. It is clear that large regional as well as global scale damages and risks are very likely to occur well before this level of warming is reached. Although no quantification of the full scale of human damage is yet possible, the picture that emerges challenges an often-implicit assumption that climate change will not significantly undermine economic growth.
The report is available at http://climatechange.worldbank.org/