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GEO 702 Lecture 5 - Fall 2018
Uploaded: A week ago
Contributor: batman2197
Category: Geography
Type: Lecture Notes
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Department of Geography and Environmental Studies GEO 702 Technology and the Contemporary Environment Fall 2018 Lecture 5 Instructor: Dr. Mohammad Manshouri 1 Source: 2 Grinnell Glacier, Glacier National Park, 1900 and 2008 • Snow and ice reflect the sun’s energy back to space. Without this white cover, more water can evaporate into the atmosphere where it acts as a greenhouse gas, and the ground absorbs more heat. Snow and ice are melting at rates unseen for thousands of years. In Glacier National Park, in the U.S. state of Montana, there were 150 glaciers in 1850. Today, there are 26. • Sea ice is diminishing too, especially in the Northern Hemisphere. Satellites have seen average Arctic sea ice shrink by 2.7% per decade from 1978 to 2006, with faster melting in summer. 3 1875 2004 Pasterze Glacier (Longest glacier in Ausrtia and in Eastern Alps, approximately 8.4 kilometers in length) 4 Portage Glacier, U.S. state of Alaska 5 This time series, based on satellite data, shows the annual Arctic sea ice minimum since 1979. The September 2010 extent was the third lowest in the satellite record. Source: 6 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 7  The oceans will continue their rise in the coming century. The Intergovernmental Panel on Climate Change (IPCC)’s best estimates range from a few inches to a few feet by 2100. • If the rise is 2 feet, the US could lose 10,000 square miles, If they rise three, they will inundate Miami and most of coastal Florida. • Sea-level rise also increases coastal erosion and the loss of coastal wetlands, and saltwater spoils freshwater drinking supplies. • Coastal populations become even more vulnerable to storm surge and flooding. • Considering that half of the world’s population lives near coasts, sea-level rise is a serious concern. • The big unknown in all this is how much the planet’s ice sheets will melt. 8 What If All The Ice Melted On Earth? ft. Bill Nye 9 Philippines evacuates thousands ahead of Super Typhoon Mangkhut 10 11 12 Philippine typhoon leaves up to 10,000 dead in Tacloban city Massive relief efforts underway as police secures areas from looting The Associated Press Posted: Nov 10, 2013 6:19 AM ET Last Updated: Nov 11, 2013 1:06 AM ET dead-in-tacloban-city-1.2421580 13 Direct Observations of Recent Climate Change Some aspects of climate have not been observed to change: Tornadoes Dust-storms Hail Lightning Antarctic sea ice 14 Forget climate Apocalypse. There's hope for our warming planet | Jelmer Mommers | TEDxMaastricht 15 Introducing IPCC • The Intergovernmental Panel on Climate Change (IPCC), the group that produces the main reports on climate change, is a scientific intergovernmental body set up by the World Meteorological Organization (WMO) and by the United Nations Environment Program in 1988. 16 Source: 17 18 Source: • The IPCC process involves hundreds of scientists from about 140 countries, a variety of fields, and a range of views. • Their function is to: – assess the latest peer-reviewed literature, – compare different computer model results from various sources, and – achieve consensus about where the weight of the evidence points and where uncertainties lie. 19 2007 Conclusions • Warming of the climate system is unequivocal. • Very high confidence that global average net effect of human activities since 1750 one of warming. • Human-caused warming over last 30 years has likely had a visible influence on many physical and biological systems. • Continued GHG emissions at or above current rates would cause further warming and cause many st changes in the global climate system during the 21 century that would very likely be larger than those th observed during the 20 century. 20 Consensus? • Do we know enough about the drivers of climate to know what causes change? • Are we underestimating the Earth system’s complexity ? • Can models accurately simulate the complex climate system? • Are there processes that will limit warming naturally? 21 On the other hand… • Arctic sea ice melting faster than predicted. • Fossil fuel emissions exceeded most IPCC projections. • Are assumptions about global energy use, too optimistic? • How quickly can developing countries reduce GHG emissions? • Calculations do not include unexpected melting in Greenland and Antarctica. 22 What do climate scientists really think? A survey conducted in 2007 by George Mason University of U.S. scientists, who have expertise in climate science, what they think.  97% of the 489 respondents agreed that “global average temperatures have increased” during the past century. That’s up from 60% in 1991. 23  84% believe human activities are causing the warming, and only 5% disagree.  So the survey does indicate the bulk of climate scientists—those most knowledgeable about the field—now agree that human activity contributes to global warming. 24 President Obama destroys Republicans over Climate Change!! 25 Senator James Inhofe 26 Details on strategies: • Efficient vehicles: Double car fuel efficiency in 2055 from 30 miles per gallon (mpg) to 60 mpg • Reduced vehicle use: Halve the miles traveled by the world’s cars in 2055 • Efficient buildings: Cut emissions by 25% in all buildings • CCS electricity: Capture and store carbon from 800 large coal power plants or 1600 large natural gas power plants • Nuclear capacity: Triple the world’s current nuclear capacity • Solar electricity: Increase solar capacity 700 times • Forest storage: Halve global deforestation and double forest planting in 50 years • Soil storage: Apply carbon management strategies to all of the world’s farm fields 27 • The previous list represents only some of the possible strategies, but choosing strategies will not be easy. • However, the longer we wait to reduce emissions, the higher the target will need to be, and the more adaptation will be necessary. • In 2004, when the wedges concept was first introduced, the target was only 7 billion tons. 28 8 technologies that could save 8 billion tons, or 8 wedges, of carbon. Some of these we could do right away, while others are based on technologies still being studied, such as capturing and storing carbon. 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 29 • There are many ways, society can do to reduce carbon emissions, but there is no single solution. • Many of the strategies are the realm of governments. • And the ever-growing world population means that we’ll have to work that much harder to reduce global emissions. • But on an individual level, there are many things we can do to make a difference. 30 Individual actions I. Tune up your furnace. II. Unplug appliances or plug into a power strip and switch it off. III.Buy water-saving appliances and toilets; installing low-flow shower heads. IV.Caulk, weather-strip, insulate, and replace old windows. V. Buy products with a Energy Star label. 31 An increase in global average temperatures greater than 2 ˚C above pre-industrial levels would result in further melting of glaciers and Arctic ice, continued rising sea levels, more frequent and extreme weather events, difficulties for global agriculture and changes in plant and animal life, including extinctions. (Credit: mariusz kluzniak via Flickr) 32 Paris climate agreement • The Paris Agreement, or Paris climate accord and Paris climate agreement, is an agreement within the United Nations Framework Convention on Climate Change (UNFCCC) dealing with greenhouse gas emissions mitigation, adaptation and finance starting in the year 2020. 33 Paris climate agreement (Cont’d) • The language of the agreement was negotiated by representatives of 195 countries at the 21st Conference of the Parties of the UNFCCC in Paris and adopted by consensus on 12 December 2015. • As of June 2017, 195 UNFCCC members have signed the agreement, 148 of which have ratified it. 34 Paris climate agreement (Cont’d) • In the Paris Agreement, each country determines its own contribution it should make in order to mitigate global warming. • There is no mechanism to force a country to set a specific target by a specific date. 35 Aims • The aim of the convention is described in Article 2, "enhancing the implementation" of the UNFCCC through: –"(a) Holding the increase in the global average temperature to well below 2 °C above pre- industrial levels and to pursue efforts to limit the temperature increase to 1.5 °C above pre- industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change; 36 –(b) Increasing the ability to adapt to the adverse impacts of climate change and foster climate resilience and low greenhouse gas emissions development, in a manner that does not threaten food production; –(c) Making finance flows consistent with a pathway towards low greenhouse gas emissions and climate-resilient development.” 37 How Technology Can Help Combat Climate Change 38 Summary (Observations) • Global surface temperatures have risen by about 0.6°C since 1900. • It is likely that this warming is larger than for any century since 200AD, and that the 1990s were the warmest decade in the last millennium. • The warming differs in different parts of the world, but over the last 25 years, almost everywhere has warmed, and very few places have cooled. 39 Summary (Observations) Cont’d • Other changes have occurred, e.g.: –Sea level has risen by about 20 cm, –Ocean heat content has increased, –Almost all mountain glaciers have retreated • Coincident with this global warming, levels of CO (and other ‘greenhouse’ gases) have 2 dramatically increased, to levels higher than those experienced for maybe millions of years. 40 • As with all science that affects our lives, we need to be educated consumers. Do your homework, starting with the IPCC reports. All of the reports provide interesting information, although they are lengthy and quite technical. 41 Also look at the work from other authoritative sources such as the National Academies of Science. ( • When looking at information (particularly on the Web), search out contrasting opinions to see what others say about a topic. • And evaluate the source—is it someone with real expertise, or just someone with an opinion. 42 Key Sources of Information The Intergovernmental Panel on Climate Change (IPCC) ( Authoritative reports supported by >95% of climate scientists Sixth assessment report (AR6) 43
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