1. Global Change Rodel D. Lasco

2. What is Global Change? Global changes are environmental changes that threaten the capacity of the whole earth system to sustain life

3. What is Climate Change? UNFCCC: “Climate change: a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods” IPCC: “any change in climate over time, whether due to natural variability or as a result of human activity”.

4. What can we do? Reduce fossil fuel emissions Control deforestation Promote forest conservation and tree planting

6. Land use and cover change Land cover refers to vegetation and other materials that cover the surface of the Earth In recent decades, the scale of land cover and ecosystems change has accelerated

7. Forests land conversion

11. Impacts of forest loss Biodiversity loss Accelerated soil erosion Impaired hydrology Poverty in the uplands

13. Interannual climate variability most famous is ENSO (El Niño-Southern Oscillation) phenomenon exceptionally strong warm current intervals increased rainfall in east Pacific and drought in west Pacific recurs every 2-9 years 1982-83 El Niño episode: damages in the country reached US$ 450 million

15. Ozone depletion Life on Earth is protected from harmful ultraviolet solar radiation by the ozone layer located between 20 and 40 km In 1974, it is discovered that chlorine- containing compounds such as chlorofluorocarbons (CFCs) and halons could damage the stratospheric ozone layer One chlorine atom from a CFC molecule can destroy thousands of protective ozone molecules

16. Ozone (cont) Satellite imageries have revealed the presence of a seasonal “ozone hole” above the Antarctic stratosphere Increased UV radiation has harmful effects on human health, fish populations, and many terrestrial and marine ecosystems. Impacts on humans and other animals include: immune system suppression, cataracts and epidermal lesions, reduced vitamin D synthesis, and cancer.

17. Ozone (cont) The global community responded to the threat of ozone depletion through the Vienna Convention and the Montreal Protocol.