He wants to show people how human activities have altered, for better or worse, our experience of the earth's natural topography.

Volcanic activity has altered the distribution and abundance of the vegetation.

AS climate experts firm up their view that human activity is seriously altering the atmosphere, one voice stands out in clarion dissent.

Human activity has altered the forest composition significantly since European settlement.

Their spirited activity is altering the face of the country.

Human activity is altering the dynamics and functioning of the Earth system to a degree never before seen.

This pre-Roman activity would have altered the natural landscape quite markedly, mostly through the felling of timber to clear fields and construct buildings.

Hydrothermal activity has altered many rocks in the caldera, transforming them into travertine and clay.

Now a new analysis suggests that human activity is also altering the way some clouds form, perhaps intensifying their sun-blocking, planet-cooling effect.

All this testifies to the difficulty of restoring natural processes once human activity has drastically altered them.