14.8 NOTES Greenhouse Gases

B.11 – Greenhouse Gases and Global Change - Greenhouse effect will maintain Earth’s temp as long as the levels remain fairly constant. - Spiraling up - warm weather produces more CO2That extra CO2 absorbs more IRThe extra IR warms the air produces more CO2absorbs more IR warms the air…….

Hydrologic cycles - needs to maintain temperature to keep water as a liquid, not as a gas - Increases amounts of water vapor will increase temperatures due to the absorption and release of IR, which is another upward spiral. This can lead to warmer temperatures.

Human activity also produces N2O (dintrogen monoxide) and CH4 (methane) via agricultural activities. - Fluorocarbons also produce warming effects in the Earth’s atmosphere.

Temperature Increases 1998 was the warmest year on record – the 10 warmest years of the 20th century were in the last 15 years unchecked CO2 generation could raise average temp .8 to 2.9 °C in next 50 years and up to 5.8 °C in the next century Scientists are in disagreement about what causes the warming The Earth’s surface isn’t warming at the same rate as the lower atmosphere Circulating ocean water transports energy from oceans and send it to the land.

- Possible Impact - Oceans can rise 5 cm each decade - A 30 years 15 cm rise could cause flooding in coastal cities - Reduced soil moisture and decreased precipitation in the summer - Northern areas would have longer growing season - Southern areas would switch to warm winter crops.

- What can be done - Framework Convention on Climate Change 1992 - developed policies and procedures to reduce greenhouse gas emissions. - Kyoto Protocol - reduce gas emissions - developing energy efficient strategies and technologies - developing alternate manufacturing processes - focus on green chemistry