BIG DUE DATES! SCHEDULE MEETING TIMES TO DISCUSS RAC: SIGN UP TO MEET! Final Draft of IA Due: Feb - 16. (Friday – 1am) Last Chance to See Due MARCH 9th Chapter Summaries & Favorite Quote Come sign out a book!!

OUR NEXT FEW DAYS AGENDA NEXT FEW WEEKS 2/2 – data and graphs due/chasing ice movie 2/6 – Energy source Research + Test Review sheet 2/8 Ecological Footprints + Activity 2/10 – Last Chance to See Summaries/Test Review 2/13 – Touch Base Day.. 2/14 – ATM TEST

Raw Data: Table

Topic: 5 – Atmosphere A.S.: DD – Greenhouse Effect & Climate Change Topic: 5 – Atmosphere A.S.: DD –

Greenhouse Effect A natural process that traps heat near the earth’s surface and prevent from radiating back into space. Is this a good or bad thing? Without the greenhouse effect, the earth’s surface would be ___________ degrees cooler than it is now. What would the effect of no greenhouse effect? About 63o F colder than it is right now

Greenhouse gases Gases that prevent the heat from radiating into space are called greenhouse gases. What are the three major greenhouse gases? Others include Tropospheric Ozone, CFCs, and Nitrous Oxide What layer of the atmosphere are these gases located in?

How the greenhouse effect works The sun’s energy comes to the earth as short-wave ultraviolet radiation(UV) . The earth converts short wave radiation to long-wave infrared radiation (heat) . As the earth radiates the heat back out, some escapes into space, but the greenhouse gases absorb and re-radiate some of the heat back to Earth. Why is this process important for life on earth? How could this process go wrong?

The last ice age What is the average temperature of the earth now? How much colder was the average temperature of the earth during the last ice age? When was the earth’s last ice age? What did the earth look like during the last ice age? Ave temp = About 3-5o colder than it is right now About 10,000 years ago

Global climate warming/change What is climate? Global warming is the increase of the average surface temperature of the earth. According to the Intergovernmental Panel on Climate Change (IPCC), the average surface temperature rose 0.74 degrees F between 1906 and 2005. - why is this such a big deal? Global climate change includes changes in many different characteristics that make up climate - such as?

Causes of global warming Global warming has been linked to an increase in the production of greenhouse gases. What are the sources of these greenhouse gases? CO2 = Methane = Nitrous oxide =

Effects of Increased Temperatures Weather – Melting ice – Rising sea levels – Biomes – Rising sea levels = climate refugees

Varying Effects The potential impacts of Climate Change may vary from location to location. Why? Some may perceive benefits. Water availability Level of industrialization…..ability to deal with changes and severe weather; ability to afford alternative energies; human health (mosquitos, etc) Increase or decrease in crops Living in polar regions Living in areas with high biodiversity Living near coral reefs Living near a coast

Glacier Reduction 1920: Photograph by unknown photographer in the collection of the National Snow and Ice Data Center/World Data Center for Glaciology. Public domain by virtue of age. [1] August 8th, 2005: Photograph by Bruce F. Molnia of the USGS, in the collection of the National Snow and Ice Data Center/World Data Center for Glaciology. Public domain as a work of the US government. [2] Glacier Bay National Park, Alaska

Glacier Reduction Expansion of habitats available for temperate species Glacier Bay National Park, Alaska

Glacier Reduction Loss of ice habitat

Feedbacks Positive Feedbacks in the Tundra Negative Feedback Ice melting: Permafrost melting: Negative Feedback Albedo Effect:

Tipping Point Due to the long time lags associated with these positive feedbacks, the global temps would continue to increase even if we immediately stopped releasing GHGs. What do scientists mean when they say we could be approaching a “tipping point” in terms of global warming? changes from one state to another (a point of no return) mass extinction of species, dramatic sea level rise, extensive droughts and the transformation of Biomes.

How do we study climate change? Collect present data - such as? How do we compare present data to the past, when no data was collected? 1. Ice - 2. Sediments/Fossils - 3. Tree rings -

How do we study climate? Air bubbles in ice cores retain atmospheric gases present when the ice was formed. CO2 measured continuously at Mauna Loa Observatory since 1958 has provided strong evidence for atmospheric change. Annual tree rings not only indicate tree age, the ring width indicates growth spurts due to warmer temperature.

Actual measurements Mauna Loa, Hawaii