The increasing frequency and severity of extreme weather events could cost the world 328 billion euros ($421 billion) per year by 2030, the Red Cross and the European Commission warned on Monday.

“Disasters take lives and ruin prospects, often making the situation of already impoverished people even worse,” said European Union Commissioner for International Cooperation, Humanitarian Aid and Crisis Response Kristalina Georgieva in a news release from the Red Cross on Monday.

The warning came as the Red Cross—a global humanitarian aid charity—and the European Commission—the executive body of the European Union—launched a joint communications campaign on the importance of preparing for disasters.

In the last 20 years, the impact of extreme weather has affected 4.4 billion people worldwide, killing 1.3 million people and causing 1.5 trillion euros in economic losses, according to the Red Cross. It calculates that every 0.77 euros spent on disaster risk reduction saves 11.47 euros in return.

This year, several European countries have suffered severe flooding. In May, floods hit entire regions of Bosnia and Herzegovina and Serbia, resulting in several dozens of casualties in both countries. Damages and economic losses amount to around 2 billion euros in Bosnia and 1.5 billion euros in Serbia.

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Earlier in the year, heavy storms flooded around 6,000 homes in the U.K. The country experienced the wettest January on record and widespread flooding continued into February.

The Red Cross/European Commission warning came one day ahead of the United Nations’ Climate Summit in New York.

Although the Red Cross drew no direct link between extreme weather events and climate change in its news release, it forecast that around 375 million people would be hit by climate-related disasters each year by 2015.

Last week, a report by the Global Commission on the Economy and Climate concluded that action against climate change need not sacrifice economic growth—despite widely held views to the contrary.

“The low-carbon growth path can lead to as much prosperity as the high-carbon one, especially when account is taken of its multiple other benefits: from greater energy security to cleaner air and improved health,” concluded the 70-page Better Growth Better Climate report, which was published last Tuesday.

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World energy demand will grow by a third by 2030, according to Felipe Calderon, the former president of Mexico who chairs the global; climate commission. During that time, some $90 trillion is seen being invested in infrastructure affecting the world’s cities, land use and energy systems.

For climate change activists like Calderon, this represents an opportunity to move away from reliance on high-carbon pollutants.

At present, carbon usage varies widely across developed world cities. According to Calderon, carbon emissions per person from public and private transportation in Atlanta, Georgia, are 10 times higher than in Barcelona, Spain. The U.S. city is marked by urban sprawl and spotty public transport, while Spain’s second-biggest city is more compact and has invested heavily in mass transit.

“We are not suggesting decoupling economic growth from energy demands; but decoupling from carbon emissions,” said Calderon.

“Although many jobs will be created, and there will be larger markets and profits for many businesses, some jobs will also be lost, particularly in high-carbon sectors,” said the authors of the report.