With earthquakes, heat waves, floods and snowstorms affecting 208 million people, killing nearly 300,000, and costing US$110 billion in losses last year alone, the General Assembly Wednesday debated mitigation steps such as building safer schools, hospitals and cities to reduce the terrible toll.

"We need to take lessons from cities and countries that have shown how to reduce risk – as well from those less fortunate, whose examples of calamity should give us all pause for thought," Secretary-General Ban Ki-moon said in opening the session, which brought together senior United Nations officials, civil society partners and city mayors.

"Experience and common sense agree: we must invest today for a better tomorrow." Ban recited the litany of natural disasters of the past year -– earthquakes in Haiti, Chile and China, floods in Pakistan and Europe, wildfires in Russia and the United States, cyclones and tropical storms in Asia.

"Barely a day went by without lives devastated, homes demolished, people displaced, and carefully cultivated hopes destroyed," he said. "It was one of the deadliest years in more than a generation."

Noting that this year may prove to be just as costly, with severe floods in Australia and Brazil showing that no country or city, rich or poor, is immune to disaster, he stressed that all too often, poorer countries suffer disproportionately and have the biggest challenges in recovering.

"Children are among the most vulnerable," he declared. "Thousands died last year as earthquake, flood or hurricane reduced their schools to rubble. These deaths could have been prevented. Lives can be saved by advance planning – and by building schools, homes, hospitals, communities and cities to withstand hazards. Such measures to reduce risk will grow ever more important as our climate changes and extreme events become more frequent and intense."

Ban cited Australia as an example of the importance of investing in disaster risk reduction. The state of Queensland escaped relatively unscathed from one of the largest cyclones to hit the country in living memory, partly due to luck since the densest population areas were spared, but also thanks to the "key role" played by planning and preparedness.

He also highlighted the UN global disaster risk reduction campaign that is already focusing on safer schools, hospitals and cities, with nearly 600 towns and cities from all regions committing to a 10-point checklist for making them more resilient.

"But so much more needs to be done," he stressed. "It will require courage, vision and leadership, and will need everyone's participation and investment."

General Assembly President Joseph Deiss also underscored the enormous toll natural disasters can exact from developing countries. "Disaster risk reduction is crucial for protecting progress made towards the Millennium Development Goals (MDGs) and for achieving sustainable development," he said, referring to the targets that seek eliminate extreme poverty and hunger, maternal and infant mortality and lack of access to medical care and education, all by 2015. "By wiping out major development gains, such as school buildings, hospitals and energy grids, disasters perpetuate a cycle of underdevelopment, poverty and disempowerment."

Reducing vulnerabilities to natural hazards requires committed efforts by all stakeholders, from local governments and international financial institutions to civil society and the private sector, he added, citing rapid urbanization, ecosystem degradation and weak infrastructure among the factors further heightening vulnerability. In the last decade, the urban population in developing countries has risen by 77 per cent to nearly 2.6 billion people.

Mayors attending the meeting included Mawardy Nurdin from Banda Aceh, in the Indonesian province of Aceh which was devastated by the Indian Ocean tsunami in 2004, which killed scores of thousands of people there and in a dozen other countries that were hit by the mammoth waves.

Many speakers referred to the 'Hyogo Framework for Action: 2005 – 2015,' which was adopted in January 2005, a month after the tsunami, by 168 countries attending the UN World Conference on Disaster Reduction in Kobe, Japan. The 10-year plan calls for putting disaster risk reduction at the centre of national policies, strengthening the capacity of disaster-prone countries to address risk, and investing heavily in disaster preparedness.