The Greenhouse Effect The Greenhouse Effect Past and

The Greenhouse Effect

The Greenhouse Effect

Past and future CO 2 atmospheric concentrations

Variations of the Earth’s Surface Temperature

Climate Change “Climate Change is the most important environmental problem we face … With so much more knowledge, the changes humans are making to the climate are turning out to be bigger than we ever expected. ” Sir. John Houghton Professor of Atmospheric Physics at Oxford Chief Executive of the Meteorological Office Chair of the Royal Commission on Environmental Pollution Chair of the Scientific Assessment Panel of the Inter-Governmental Panel on Climate Change

The Inter-Governmental Panel on Climate Change 4 th Assessment Report 2007 2500+ scientific expert reviewers 800+ lead authors from 130+ countries 6 years work 4 volumes 1 unanimous report

IPCC - the Main Headlines 99%+ certainty that CO 2 levels are beyond natural range of last 650, 000 years. 90%+ certainty that human activity has played the dominant role in warming the climate. 2° – 4. 5°C temperature rise during 21 st century (but more in some areas, less in others) 18 -59 cm sea-level rise in 21 st century (not including new melt-water from ice-caps)

Just in case you’re still unsure …

Sir Nicholas Stern “The impacts are inequitable: poor countries will be hit hardest and earliest, when it is the rich countries responsible for ¾ of Greenhouse Gases currently in the atmosphere. ”

Current Impacts of Climate Change • 150, 000 people a year are dying • The number of Category 4 & 5 hurricanes has almost doubled in the last 30 years. • Malaria has spread to higher altitudes (e. g. the Colombian Andes, 7, 000 feet above sea level). • The flow of ice from glaciers in Greenland has more than doubled over the past decade.

Projected Impacts of Climate Change • 300, 000 people a year dying by 2030. • 200 million environmental refugees by 2050. • Heatwaves more frequent & more intense. • Extreme drought (sometimes lasting for years) will affect 10% of the planet by 2050 (rising from 2%). • Arctic Ocean ice-free in summer, maybe by 2015. • Up to a million species extinct by 2050. • “abrupt & irreversible” Climate Change - IPCC

Deforestation S. Bahia (Brazil) 1945

Deforestation S. Bahia (Brazil) 1990

Major wildfires by decade, 1950 -2000

Major floods per decade 1950 -2000

Wildlife threatened with extinction Chapin et al. , 2000

The Big Picture. . . • If each person is entitled to an equal share of the earth’s resources, we in the UK used up our share by April 16 th 2006 (Easter Sunday). • if everyone lived like us, we’d need 3+ planets • world’s richest 20% income = 74 x poorest 20% • world’s richest 20% consume 16 x poorest 20%