The Haiti earthquake and the Russian summer heat wave made 2010 one of the deadliest years for natural disasters in more than two decades, but future years could be worse, a United Nations agency has warned.

More than 296,800 people were killed in 373 natural disasters last year, which affected nearly 208 million others and cost nearly $110 billion in overall losses, according to annual data from the Centre for Research on the Epidemiology of Disasters (CRED).

A press release quotes Margareta Wahlström, head of UNISDR and Secretary-General Special Representative for Disaster Risk Reduction:

These figures are bad, but could be seen as benign in years to come. Unless we act now, we will see more and more disasters due to unplanned urbanization and environmental degradation. And weather-related disasters are sure to rise in the future, due to factors that include climate change.”

Ms. Wahlström goes on to stress that disaster risk reduction is no longer optional:

It’s critical for local governments, city leaders and their partners to incorporate climate change adaptation in urban planning.”

The Haiti earthquake was the deadliest event in 2010, resulting in more than 222,500 fatalities, while the Russian heat wave caused about 56,000 fatalities, according to CRED.

For the first time, the Americas became the world’s worst affected continent in terms of fatalities, with 74 percent of total deaths caused by the Haiti earthquake.

Even though Asia experienced fewer disaster-related deaths than the Americas or Europe, it remained the region most prone to natural disasters.

Some 89 percent of the total number of people affected by natural disasters in 2010 lived in Asia, according to CRED.

Five of the 10 most deadly disasters occurred in China, Pakistan, and Indonesia. However, the costliest event in 2010 was the earthquake in Chile, with overall damages valued at $30 billion.

Check out I.I.I. facts and stats on global catastrophes.