CHAPTER 26 CLIMATE CHANGE WHEN THE TREES LEAVE Scientists grapple with a shifting climate

1. CHAPTER 26CLIMATE CHANGE WHEN THE TREES LEAVE Scientists grapple with a shifting climate

2. 26 WHEN THE TREES LEAVE Scientists grapple with a shifting climate Evidence for climate change is overwhelming, and human activity is the main driver. Changes throughout our natural environment, from species diversity to declining human health on a worldwide scale are in our own hands. Information and literacy will help us make sound policy decisions. Main Concept

3. 26 WHEN THE TREES LEAVE Scientists grapple with a shifting climate • At the end of this chapter you will know: • The difference between climate and weather. • The evidence for climate change and anthropogenic drivers is overwhelming. • Acknowledging human factors and making changes is imperative. Learning Outcomes

4. 26 WHEN THE TREES LEAVE Scientists grapple with a shifting climate Climate change is causing ice in the lakes of northern forests to melt earlier in the year, winters are coming later, some species of trees are dying off, and other species are popping up in unexpected places. Forests are at risk of becoming scrublands or savanna, prairies in Africa and the Americas are becoming deserts, coral reefs are becoming bleached, and change is happening everywhere at unprecedented speed. Case: Ham Lake in North Woods of Minnesota

5. 26 WHEN THE TREES LEAVE Scientists grapple with a shifting climate Climate change is causing ice in the lakes of northern forests to melt earlier in the year, winters are coming later, some species of trees are dying off, and other species are popping up in unexpected places. Forests are at risk of becoming scrublands or savanna, prairies in Africa and the Americas are becoming deserts, coral reefs are becoming bleached, and change is happening everywhere at unprecedented speed. Case: Ham Lake in North Woods of Minnesota

6. 26 Climate is not the same thing as weather Temperature on a given day is part of what we refer to as weather. The predictions and range of conditions we expect is based on climate. Weather is short-term and geographically limited, while climate is the larger, long-term picture. No single weather event can be attributed to global warming. However, the rapidly shifting range of temperatures that are being recorded around the world are indications of climate change associated with global warming. Dr. Lee Frelich of the University of Minnesota surveying the damage following the 75,000 acre fire at Ham Lake. http://www.forestry.umn.edu/People/Frelich/index.html

7. 26 Climate is not the same thing as weather Range shifts have happened before. As the North American ice cap retreated 12,000 years ago, tree species range shifted northward at a rate of 50 km per century. About 6000 years ago, another tree range migration occurred—this time south and west. Instead of having thousand of years to adapt as with past climate changes, tree species today might have only a few decades in which to adapt or die. Dr. Lee Frelich of the University of Minnesota surveying the damage following the 75,000 acre fire at Ham Lake. http://www.forestry.umn.edu/People/Frelich/index.html

8. 26 Evidence of global climate change abounds TERMS TO KNOW: Climate change Weather Climate Consider this: Birch trees, long established in the Minnesota north woods are dying as growing seasons get longer and soil temperatures rise. Red maple, common in Louisiana, is becoming well established in Minnesota. Spring, marked by budding, is two weeks or more ahead of historic averages for the last two decades. The National Oceanic and Atmospheric Administration (NOAA) has recorded global average land temperatures almost 2oF higher than the twentieth-century average and sea surface temperatures as much as 5oF higher in some parts of the world.

9. 26 Evidence of global climate change abounds TERMS TO KNOW: Climate change Weather Climate Consider this: Birch trees, long established in the Minnesota north woods are dying as growing seasons get longer and soil temperatures rise. Red maple, common in Louisiana, is becoming well established in Minnesota. Spring, marked by budding, is two weeks or more ahead of historic averages for the last two decades. The National Oceanic and Atmospheric Administration (NOAA) has recorded global average land temperatures almost 2oF higher than the twentieth-century average and sea surface temperatures as much as 5oF higher in some parts of the world.

10. 26 Evidence of global climate change abounds TERMS TO KNOW: Climate change Weather Climate Consider this: Birch trees, long established in the Minnesota north woods are dying as growing seasons get longer and soil temperatures rise. Red maple, common in Louisiana, is becoming well established in Minnesota. Spring, marked by budding, is two weeks or more ahead of historic averages for the last two decades. The National Oceanic and Atmospheric Administration (NOAA) has recorded global average land temperatures almost 2oF higher than the twentieth-century average and sea surface temperatures as much as 5oF higher in some parts of the world.

11. 26 Evidence of global climate change abounds TERMS TO KNOW: Climate change Weather Climate Small changes have big impact. Icebergs 200-feet tall, formerly part of the Greenland Ice Sheet, now float into the North Atlantic Ocean.

12. 26 Evidence of global climate change abounds Just a few degrees warmer and we see big effects—especially in the Arctic. Temperature change is not evenly distributed. Researchers evaluated weather patterns of Ellismere Island in the Arctic and found that spring and summer temperatures were 20−29oF higher than in previous years. This difference is equivalent to locations 1000−1400 miles farther south. Rising sea levels have already displaced hundreds of thousands of people.

13. 26 Evidence of global climate change abounds

14. 26 Evidence of global climate change abounds Warmer temperatures can be expected to lead to weather extremes.

15. 26 Evidence of global climate change abounds

16. 26 Evidence of global climate change abounds

17. 26 Evidence of global climate change abounds

18. 26 Evidence of global climate change abounds

19. 26 A variety of factors affect climate TERMS TO KNOW: Greenhouse gases Greenhouse effect Radiative forcer Albedo Positive feedback loops Greenhouse gases each have different abilities to trap heat, expressed as CO2 equivalents. Greenhouse gases include carbon dioxide, methane, and nitrous oxide. These gases maintain the Earth’s temperature—a good thing! Unfortunately, since the middle of the twentieth century, evidence of an enhanced greenhouse effect from the use of fossil fuels started to mount.

20. 26 A variety of factors affect climate TERMS TO KNOW Greenhouse gases Greenhouse effect Radiative forcer Albedo Positive feedback loops Greenhouse gases each have different abilities to trap heat, expressed as CO2 equivalents. Greenhouse gases include carbon dioxide, methane, and nitrous oxide. These gases maintain the Earth’s temperature—a good thing! Unfortunately, since the middle of the twentieth century, evidence of an enhanced greenhouse effect from the use of fossil fuels started to mount.

21. 26 A variety of factors affect climate TERMS TO KNOW: Greenhouse gases Greenhouse effect Radiative forcer Albedo Positive feedback loops The greenhouse gases are one type of radiativefactor—something that alters the balance of incoming solar radiation with heat that escapes out into space. Another influence is the ability of a surface to reflect away solar radiation. This factor, albedo, comes into play as glacier ice is lost along with its role in reflecting light.

22. 26 A variety of factors affect climate TERMS TO KNOW: Greenhouse gases Greenhouse effect Radiative forcer Albedo Positive feedback loops The greenhouse gases are one type of radiativefactor—something that alters the balance of incoming solar radiation with heat that escapes out into space. Another influence is the ability of a surface to reflect away solar radiation. This factor, albedo, comes into play as glacier ice is lost along with its role in reflecting light.

23. 26 A variety of factors affect climate TERMS TO KNOW: Greenhouse gases Greenhouse effect Radiative forcer Albedo Positive feedback loops The greenhouse gases are one type of radiativefactor—something that alters the balance of incoming solar radiation with heat that escapes out into space. Another influence is the ability of a surface to reflect away solar radiation. This factor, albedo, comes into play as glacier ice is lost along with its role in reflecting light.

24. 26 A variety of factors affect climate As surfaces with high albedo are replaced with low-albedo surfaces, warming occurs and positive feedback is triggered. Monitoring CO2 released from thawing permafrost in Alaska – long-term increases of atmospheric loading of CO2. Positive and negative feedback loops influence warming and cooling of the planet.

25. 26 A variety of factors affect climate To model and make predictions about the future climate, scientists use a wide variety of clues from ice and sediment cores, tree rings, coral reefs, and fossils. Other natural forces include volcanic eruptions and sunspot cycles. Predictable long-term cycles of the Earth’s position relative to the Sun—Milanovitchcycles—also played an important part in earlier climate-change events.

26. 26 A variety of factors affect climate To model and make predictions about the future climate, scientists use a wide variety of clues from ice and sediment cores, tree rings, coral reefs, and fossils. Other natural forces include volcanic eruptions and sunspot cycles. Predictable long-term cycles of the Earth’s position relative to the Sun—Milanovitchcycles—also played an important part in earlier climate-change events.

27. 26 A variety of factors affect climate To model and make predictions about the future climate, scientists use a wide variety of clues from ice and sediment cores, tree rings, coral reefs, and fossils. Other natural forces include volcanic eruptions and sunspot cycles. Predictable long-term cycles of the Earth’s position relative to the Sun—Milanovitchcycles—also played an important part in earlier climate-change events. .

28. 26 A variety of factors affect climate To model and make predictions about the future climate, scientists use a wide variety of clues from ice and sediment cores, tree rings, coral reefs, and fossils. Other natural forces include volcanic eruptions and sunspot cycles. Predictable long-term cycles of the Earth’s position relative to the Sun—Milanovitchcycles—also played an important part in earlier climate-change events.

29. 26 A variety of factors affect climate Direct and indirect temperature measurements are used to measure change over time. Readings from Mauna Loa laboratory go back to 1958, when Charles Keeling began taking precise CO2 readings. CO2 gas bubbles from ice cores can also be used to estimate past levels.

30. 26 A variety of factors affect climate Direct and indirect temperature measurements are used to measure change over time. Readings from Mauna Loa laboratory go back to 1958 when Charles Keeling began taking precise CO2 readings. CO2 gas bubbles from ice cores can also be used to estimate past levels.

31. 26 A variety of factors affect climate A comparison of historic CO2 levels and temperatures as determined from the Antarctic Vostok ice core, show that the two parameters have been closely aligned over the past 400,000 years. The relationship between CO2 and temperature is one of both cause and effect. In the far past, natural events triggered warming, resulting in the release of more CO2, which then caused even more warming. Regardless of the reason for the release of extra greenhouse gases, temperatures change as CO2 increases and decreases.

32. 26 Current climate change has both human and natural causes TERMS TO KNOW: Anthropogenic Intergovernmental Panel on Climate Change (IPCC) Computer models take factors known to have affected past climates to see what might be responsible for recent warming. The Intergovernmental Panel on Climate Change (IPCC) is made up of thousands of scientists from around the world who evaluate research in climate science. They agree that the Earth’s atmosphere is changing dramatically and with alarming speed. A thin slice of ice from an ice core from Antarctica. The core contains trapped air bubbles that can reveal information about the atmosphere and temperatures of the past.

33. 26 Current climate change has both human and natural causes TERMS TO KNOW Anthropogenic Intergovernmental Panel on Climate Change (IPCC) Computer models take factors known to have affected past climates to see what might be responsible for recent warming. The Intergovernmental Panel on Climate Change (IPCC) is made up of thousands of scientists from around the world who evaluate research in climate science. They agree that the Earth’s atmosphere is changing dramatically and with alarming speed. A thin slice of ice from an ice core from Antarctica. The core contains trapped air bubbles that can reveal information about the atmosphere and temperatures of the past.

34. 26 Current climate change has both human and natural causes NASA satellite reveals that 2011’s minimum sea ice extent in the Arctic Ocean, reached on September 9, 2011, as depicted here, was far smaller than the 30-year average (yellow) and opened up Northwest Passage shipping lanes (in red).

35. 26 Some tree species are already migrating north; that doesn’t mean they will survive TERMS TO KNOW: Anthropogenic Intergovernmental Panel on Climate Change (IPCC) Species have evolved to live and thrive in a certain habitat. If the climate is changing enough to alter ecosystems, we expect to see species responding by changing where they live or the timing of important temperature-dependent biological events.

36. 26 Some tree species are already migrating north; that doesn’t mean they will survive TERMS TO KNOW: Anthropogenic Intergovernmental Panel on Climate Change (IPCC)

37. 26 Some tree species are already migrating north; that doesn’t mean they will survive TERMS TO KNOW: Anthropogenic Intergovernmental Panel on Climate Change (IPCC)

38. 26 Some tree species are already migrating north; that doesn’t mean they will survive TERMS TO KNOW: Anthropogenic Intergovernmental Panel on Climate Change (IPCC)

39. 26 Some tree species are already migrating north; that doesn’t mean they will survive TERMS TO KNOW: Anthropogenic Intergovernmental Panel on Climate Change (IPCC)

40. 26 Some tree species are already migrating north; that doesn’t mean they will survive TERMS TO KNOW: Anthropogenic Intergovernmental Panel on Climate Change (IPCC) Species’ responses, such as shifting ranges or earlier blooming and hatching, may be the best evidence that climate is actually changing. It is unlikely that these temperature-dependent events would change in this way if the planet were not getting warmer.

41. 26 Some tree species are already migrating north; that doesn’t mean they will survive TERMS TO KNOW: Anthropogenic Intergovernmental Panel on Climate Change (IPCC) The blue-gray gnatcatcher has moved more than 300 km north since the 1970s.

42. 26 Some tree species are already migrating north; that doesn’t mean they will survive TERMS TO KNOW: Anthropogenic Intergovernmental Panel on Climate Change (IPCC) Sugar maple trees are moving north.

43. 26 Some tree species are already migrating north; that doesn’t mean they will survive TERMS TO KNOW: Anthropogenic Intergovernmental Panel on Climate Change (IPCC) Winter temperatures are no longer low enough to kill off bark beetles.

44. 26 Climate change has environmental, health, and economic consequences As forests change to savanna or as losses due to fires outside of the normal cycle continue to mount, the direct economic impact for the Boundary Waters area around Ham Lake, Minnesota, alone can be expected to top $240 million in lost wages. No longer will the area be able to support wildlife—moose, lynx, boreal owls—invaluable on their own and integral to the ecosystem functioning of northern forests. Forests stabilize soil and clear water of pollutants. Continued losses also play into a positive feedback loop that will accelerate climate change.

45. 26 Confronting climate change is challenging TERMS TO KNOW: Mitigation Carbon taxes Precautionary principle Resistance forestry is a new approach that uses techniques aimed at maintaining existing species in their current locations, despite the shifting climate. Planned burning mimics natural cycles and planting seeds instead of saplings builds tougher populations. Field-grown seedlings are hardier and have a better chance of surviving changes. Minimizing the damage is one strategy; limiting the amount of CO2 entering the atmosphere is another. Researchers Pacala and Socolow from Princeton University have propose the “stabilization wedge,” whereby any eight of fifteen steps would stabilize in the atmosphere.

46. 26 Confronting climate change is challenging TERMS TO KNOW: Mitigation Carbon taxes Precautionary principle Resistance forestry is a new approach that uses techniques aimed at maintaining existing species in their current locations, despite the shifting climate. Planned burning mimics natural cycles and planting seeds instead of saplings builds tougher populations. Field-grown seedlings are hardier and have a better chance of surviving changes. Minimizing the damage is one strategy; limiting the amount of CO2 entering the atmosphere is another. Researchers Pacala and Socolow from Princeton University have propose the “stabilization wedge,” whereby any eight of fifteen steps would stabilize in the atmosphere.

47. 26 Confronting climate change is challenging TERMS TO KNOW: Mitigation Carbon taxes Precautionary principle Minimizing the damage is one strategy; limiting the amount of CO2 entering the atmosphere is another. The IPCC has several climate-change response scenarios that predict how much the climate will change based on how the human population responds.

48. 26 Confronting climate change is challenging TERMS TO KNOW; Mitigation Carbon taxes Precautionary principle Researchers Pacala and Socolow from Princeton University have propose the “stabilization wedge,” whereby any eight of fifteen steps would stabilize in the atmosphere.

49. 26 Confronting climate change is challenging TERMS TO KNOW Mitigation Carbon taxes Precautionary principle Researchers Pacala and Socolow from Princeton University have propose the “stabilization wedge,” whereby any eight of fifteen steps would stabilize in the atmosphere.

50. 26 Confronting climate change is challenging TERMS TO KNOW Mitigation Carbon taxes Precautionary principle Researchers Pacala and Socolow from Princeton University have propose the “stabilization wedge,” whereby any eight of fifteen steps would stabilize in the atmosphere.