World in Our Hands

1600 × 1048

Hourglass with City and Ice

1534 × 1293

Earth Day 2012 celebration

1600 × 900

Pollution and environmental crisis

1280 × 1024

Pollution and environmental hazards

1280 × 1024

Nuclear Power Plant Cooling Towers — Gray

1200 × 960

Penguins in a polluted alley

1280 × 800

Polar bear in urban alley

1024 × 768

Penguins in a polluted alley

1200 × 827

Polar bear in urban alley

1024 × 768

Earth on fire

1440 × 900

Monkey and Child Face

1024 × 768