Floods, droughts, earthquakes, hurricanes and fires have plagued us throughout history. But lately they've been occurring more often, and they've been hitting harder. These changes aren't random: humans are playing their part.

In recent years, the rate at which natural disasters have occurred has increased, and they've tended to cause more damage. The change is more than just a statistical blip. The effect of human activity on the environment, in rich and poor countries alike, is tending to make natural disasters worse.

Deforestation, for instance, can worsen the impact of floods: water moves faster over deforested land, and less of it is absorbed into the ground, than on forested land. In the process, precious topsoil is washed away, making land less fertile for farmers. With too few trees to hold the soil together, landslides and mudslides can occur.

Another example: there's strong, credible scientific evidence that indicates a link between pollution (including carbon emissions), global warming and changing rainfall patterns. Less rain is falling on some parts of the earth, and more of it on others.

If human activity is part of the problem, human activity can also be part of the solution. Wealthy nations like Australia can act to reduce pollution, including carbon dioxide emissions from cars and power plants.

With our help, communities in poorer countries can become less vulnerable to natural disasters by combating their poverty. There are many ways that poor communities can prepare ahead of disasters so that when they hit the damage is not so severe. Aid and development programs can include training in ways to farm and work that sustain and restore, rather than strip, the environment.