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Global warming is a critical issue marked by rising temperatures and climate changes due to human activities, especially fossil fuel emissions. The Intergovernmental Panel on Climate Change emphasizes the urgent need for action, as we are already witnessing unprecedented weather events and biodiversity loss. Solutions include enhancing energy efficiency, investing in renewable energy, and implementing carbon capture technologies. We must collaborate globally to limit emissions and secure a healthier planet for future generations. Will we take action for our children’s future?
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Global Warming • What is it? • What’s causing it? • What are the solutions?
CO2: one of the main heat-trapping gases. Its concentration in the atmosphere, past 250 yrs. Past 10,000 yrs
CO2 concentration: 400,000 yrs--4 ice ages.Read graph from right to left.Recent increase unprecedented, NOT a natural cycle. Present interglacial period
It’s getting warmer 2010, 2005, 1998: tied as hottest years on record. 2001-2010: hottest decade on record.
Global warming is here now! • The number of severe hurricanes has increased by 80% during past 30 yrs. • Droughts in Texas, western states. • Decrease in migratory birds, due to warmer winters in northern states. • Increase in tree mortality, Western U.S. • pH of ocean is dropping due to CO2; affects corals, shellfish. • Range shifts of MANY biological species. • Forest fires are increasing, as predicted. • Prolonged dry spells. • Reduced snowpack. • More rain, more extreme rain. • Polar bear now “endangered.” • Bacterial “blooms” in waters. • ETC!
Glacier National Park, Montana, is melting. Glacier nat park, Montanna-1 1850: 150 named glaciers. 2007: 26. 2030: 0 expected
Arctic melt extent, 1979 and 2003 Expected to be ice-free in summer by 2030. Recentlly: Melting has accelerated. “Arctic ice could be in an abrupt, irreversible decline.” Are we approaching a tipping point? Reflectivity feedback could have serious consequences for Greenland.
James Hansen, NASA’s chief climatologist, GW expert: Earth could pass a “tipping point” during next 10 to 20 yrs that would initiate irreversible melting of the Greenland and W Antarctic ice caps, raising sea levels by 50 feet over the next few centuries and “produce a new planet.”We could see 10-ft rises by the end of this century.
Is this what you want for your grandchildren?It’s a moral issue!
What’s causing the warming? When we look at the patterns of global changes (temps, ice, rainfall, etc.) …..
…we find that natural sources cannot explain it, but human-emissions of greenhouse gases do. Intergovernmental Panel on Climate Change (IPCC): • “Unequivocal” that climate is warming, • “Very likely” that human activities are major driver.
The cause: mostly fossil fuels Carbon in atmosphere
IPCC Report: A conservative document • Spons by U.N. & World Meteorological Org • ~3000 scientists compile the 6-yr reports • Based on tens of thousands of peer-reviewed scientific papers published in hundreds of scientific journals • Results arrived at by consensus
The major U.S. carbon polluters: Electric Power 41% Transportation 33% 3/4 from coal 3/4 from cars and trucks
COAL • 1 plant = 1 million cars SOLUTIONS: • Energy efficiency & alternative energy sources • Carbon capture & storage! (~50% price incr) • Congress could mandate CCS
CARS • 6 tons of CO2 / yr, 3 X car’s weight! SOLUTIONS: • 55 mpg by 2020 (hybrids today) • Plug-in hybrids, attached to renewable electricity • Gasoline tax of several $ per gallon • “Externalities” of driving: $12 per gallon!
The Solutions: Reduce CO2 emissions: Efficiency (use less) Renewables (solar, wind) Nuclear power Carbon capture and storage More broadly: Preserve, replant forests Limit population growth
Pedestrian zones, pedestrian streets
Geothermal energy For electricity: For heating & cooling:
Biofuels From corn today: bad idea! With research: biofuels from grasses… … and agri waste
Also: Nuclear power • No greenhouse gases ! • Serious drawbacks (proliferation etc.) • MUCH safer than fossil fuels. China, India
20 leading climate scientists published a paper in Naturein Sep 2009: • Our present 390 ppm atm CO2 concentration is already unsustainable and dangerous. • We need to move it back to 350 ppm asap, in order to hold the temp increase to 2oC. James Hansen, NASA’s cilmatologist Paul Crutzen Nobel Prize, Chem.
What’s needed: • 60% global emissions reduction by 2050. • Converge on 1.5 tons / person-yr • India: emits 1 ton / person-yr today • US: emits 20 tons / person-yr --must reduce by 90% • Europe: reduce by 80%. • But emissions are increasing, not decreasing!
THANK YOU! Thank you ART HOBSON ahobson@uark.edu Website: physics.uark.edu/hobson We’re all in this together!