1. Past climate and environmental data is derived from natural sources that inform us about Earth’s climate thousands to millions of years ago. Proxy data is data that stands in for instrumental records from weather stations, balloons, and satellites. Paleoclimatic data is therefore proxy data.
2. “History really does matter – if something happened in the past, it must have been possible, it should be understood, and it can be used to test our understanding.” If humans are changing the climate, we should be able to rule out other things that caused the climate to change before.
3. Coral Ocean and lakes sediments Fossilized pollen Fossilized plants Fossilized shells Tree Rings/Fire history Ice Cores Cave deposits Loess and Eolian
4. Ocean and lakes sediments Fossilized plants Fossilized shells Fossilized pollen Ice CoresMost of the following materials come from theNational Climatic Data Center:http://www.ncdc.noaa.gov/
5. Between 6 and 11 billion metric tons of sediment accumulate in the ocean and lake basins each year. Scientists drill cores of sediment from the basin floors. Ocean and lake sediments consist of materials that were produced in the lake/ocean or that washed in from nearby land. These materials (preserved tiny fossils and chemicals in the sediments) can be used to interpret past climate.
7. Shell prevalence and composition tell us about chemical composition of the atmosphere and ocean as well as temperature.
8. Each species and genus of plants producespollen grains which have a distinct shape.These shapes can be used to identify the typeof plant from which they came. Inferences canthen be made about the climate based on thetypes of plants found in each layer.
9. Located high in mountains and deep in polar ice caps, ice has accumulated from snowfall over many centuries. Scientists drill through the deep ice to collect ice cores. These cores contain dust, air bubbles, or isotopes of oxygen, that can be used to interpret the past climate of that area.http://www.youtube.com/watch?v=oHzADl-XID8
10. Ruling out cosmic and geological activity.
11. Space dust Solar stuff Cosmic rays Volcanoes Continental drift What’s left?
12. Ocean and lake sediments and ice coresProxy data that contains information on what?
13. Meteorite, asteroid, and comet impacts. ~65 m.y.a. an asteroid 6 miles wide hit the Yucatan peninsula blasting a crater 110 miles wide and blanketing the Earth with an ash cloud.
14. The sun changes little over short time scales accounting. May slightly affect El Niño and La Niña patterns in the Pacific. El Niño is characterized by unusually warm temperatures and La Niña by unusually cool temperatures in the equatorial Pacific.
15. While El Niño and La Niña can have warming and cooling impacts at the equator of a couple of degrees Celsius, current science estimates the sun’s influence on these is a few tenths of a degree Fahrenheit.
16. Rays from deep space and solar wind interact with Earth’s atmosphere. This radiation’s intensity varies. It interacts with the Earth’s magnetic field. How?
17. Solar wind ionizes particles in the atmosphere. More solar wind ionizes more particles. Earth’s magnetic field shields the atmosphere and surface from solar wind. The stronger the magnetic field, the less solar wind, the less ionized the atmosphere. The interactions are traceable through magnetic alignments inSolar wind strikes the beryllium10 and magneticEarth’s magnetic field alignments in lava flows.
18. Volcanic eruptions release CO2 & sulfuric acid H2SO4 Large eruptions like Mt. Pinatubo cool the globe a few tenths of a degree for a year or two.http://www.youtube.com Mount Pinatubo/watch?v=C6_PIuIBUX8 Philippines, 1991
19. Continental drift occurs very slowly – inches per year. Topography and arrangement matter. But change is so slow it produces a negligible effect.Sequence and global location of continental platesover previous 200 million years.
20. If not… Space dust Solar output Cosmic rays Volcanoes Continental drift…what do we have to explain global warming?CO2 and other greenhouse gases.