Current climate change models predict that the world temperature could rise 4 degrees Celsius by the end of the century, a situation that would cause extreme heat waves, devastating increases in sea levels, massive crop failures and a terrible loss of biodiversity, according to a report issued Nov. 16 by the World Bank.

"A 4°C warmer world can, and must be, avoided — we need to hold warming below 2°C," World Bank Group President Jim Yong Kim said as the organization released its new report, "Turn Down the Heat: Why a 4°C Warmer World Must be Avoided." Kim, a physician and anthropologist and the former president of Dartmouth College, became the first scientist to lead the World Bank after he took office in July. "Lack of action on climate change threatens to make the world our children inherit a completely different world than we are living in today. Climate change is one of the single biggest challenges facing development, and we need to assume the moral responsibility to take action on behalf of future generations, especially the poorest."

The study, which was developed by the Potsdam Institute for Climate Impact Research and Climate Analytics for the World Bank, predicts that the worst effects of climate change will be felt in some of the planet's poorest regions, which lack the economic and scientific capabilities to adapt to a warming world. "We will never end poverty if we don't tackle climate change. It is one of the single biggest challenges to social justice today," Kim said in a call on Friday.

Among the effects anticipated by the report:

  • Average monthly summer temperatures Mediterranean, North Africa, Middle East and parts of the United States could increase 6 degrees or more.
  • Sea levels could rise up to three feet or more, affecting coastal cities in Mexico, India, Bangladesh, Mozambique, Madagascar, the Philippines and Vietnam, as well as small island nations, which could become uninhabitable.
  • Ocean acidification could cause coral reefs to stop growing or dissolve, threatening biodiversity as well as the income and food sources for humans.
  • Drought could affect 44 percent of global croplands, threatening the world's food security.
  • Water sources for humans could become scarce in northern and eastern Africa, the Middle East and South Asia.

The report does note that sustained action by the world's governments could hold temperature increases to or below 2 degrees Celsius, a goal already endorsed by much of the international community. More importantly, the World Bank takes the position that action to mitigate climate change would not only save lives, it could create economic growth opportunities. Beneficial initiatives cited by the report include increasing energy-efficiency, especially in buildings; increasing the production of renewable energy; redistributing the $1 trillion of subsidies that currently go to fossil fuel and other industries; expanding both public and private investment in green infrastructures and public transportation; and supporting carbon pricing and emissions trading schemes.

Writing in the foreword to the report, Kim said he hopes it "shocks" the world into taking urgent action against climate change.

World Bank report warns of 'devastating' effects of climate change
Current climate-change models predict that the world temperature could rise 4°C by the end of the century. The world's poorest regions will experience the wors