Presented by: Daniela Visinica

Global Climate Change Identifiable change in the climate of Earth as a whole that lasts for an extended period of time (decades or longer) –When due to natural processes, it is usually referred to as global climate variability –Usually refers to changes forced by human activities that change the atmosphere

What causes Earth’s climate to change? Changes in the atmosphere Changes in the atmosphere Natural processes Natural processes – Volcanoes – Tectonic plate movement – Changes in the sun Human activities – any activity that releases “greenhouse gases” into the atmosphere Human activities – any activity that releases “greenhouse gases” into the atmosphere What causes Earth’s climate to change?

What are greenhouse gases? Any gases that cause the “greenhouse effect!” Imagine… a car on a cool but sunny day…

Climate Change: Fitting the pieces together

Outline What changes climate? Is it real? How do we know? Why should we care? How sure are scientists? What next—what can we do?

What changes climate? Changes in: – Sun’s output – Earth’s orbit – Drifting continents – Volcanic eruptions – Greenhouse gases

“Greenhouse effect” Increasing greenhouse gases trap more heat

Greenhouse gases Nitrous oxide Water Carbon dioxide Methane Sulfur hexafluoride

Could the warming be natural?

Is it real?

Effects: Snow and ice Grinnell Glacier, Glacier National Park 1900 and 2008

Effects on precipitation

Europe’s Climate is Anormal Rahmstorf & Ganopolski, Climatic Change, : p  European temperatures are 5-10 °C higher than normal

1976–1999: Number of cold and frost days decreased Number of summer days increased Temperature Extremes Summer days (T max >= 25 °C) Changes in 1976–1999 Data-sources: ECA, IPCC, ACACIA, KMNI Projections: Cold winters disappear almost entirely by 2080 Hot summers much more frequent future projection past trends

1976–1999: Southern Europe: decrease Mid and northern Europe: increase Precipitation Extremes Very heavy precipitation days (p >= 20mm) Changes in 1976–1999 Data-source: ECA, IPCC, ACACIA, KMNI Projections: Likely more frequent droughts and intense precipitation events future projection past trends

Effects on ecosystems

How do we know?

Computer models

Why should we care?

2003 European Heat Wave Germany: Lowest river levels this century Switzerland: Melting glaciers, avalanches France: >14,000 deaths Portugal: Forest fires U.K.: Train rails buckle

Sea-level rise projections : a few inches to a few feet 2 ft: U.S. would lose 10,000 square miles 3 ft: Would inundate Miami Affects erosion, loss of wetlands, freshwater supplies Half of the world’s population lives along coasts Big question: Ice sheets

What do climate scientists really think?

What next—what can we do?

Produce more fuel-efficient vehicles Reduce vehicle use Improve energy-efficiency in buildings Develop carbon capture and storage processes Triple nuclear power Increase solar power Decrease deforestation/plant forests Improve soil carbon management strategies

Individual actions Use mass transit, bike, walk, roller skate Tune up your furnace Unplug appliances or plug into a power strip and switch it off Buy water-saving appliances and toilets; installing low-flow shower heads. Caulk, weatherstrip, insulate, and replace old windows Buy products with a EPA Energy Star label