* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Unit_3-Session_2-Modern_Climate_change
Michael E. Mann wikipedia , lookup
Intergovernmental Panel on Climate Change wikipedia , lookup
Low-carbon economy wikipedia , lookup
Climate change denial wikipedia , lookup
Soon and Baliunas controversy wikipedia , lookup
German Climate Action Plan 2050 wikipedia , lookup
Climate change in the Arctic wikipedia , lookup
Climate change adaptation wikipedia , lookup
Climate change mitigation wikipedia , lookup
Citizens' Climate Lobby wikipedia , lookup
Effects of global warming on human health wikipedia , lookup
Fred Singer wikipedia , lookup
Economics of climate change mitigation wikipedia , lookup
Climatic Research Unit documents wikipedia , lookup
Climate governance wikipedia , lookup
2009 United Nations Climate Change Conference wikipedia , lookup
Climate engineering wikipedia , lookup
Media coverage of global warming wikipedia , lookup
Climate change and agriculture wikipedia , lookup
Climate change in Tuvalu wikipedia , lookup
Climate sensitivity wikipedia , lookup
Global warming controversy wikipedia , lookup
Economics of global warming wikipedia , lookup
Global Energy and Water Cycle Experiment wikipedia , lookup
Future sea level wikipedia , lookup
United Nations Framework Convention on Climate Change wikipedia , lookup
Mitigation of global warming in Australia wikipedia , lookup
Effects of global warming on humans wikipedia , lookup
Climate change and poverty wikipedia , lookup
General circulation model wikipedia , lookup
Surveys of scientists' views on climate change wikipedia , lookup
Scientific opinion on climate change wikipedia , lookup
Politics of global warming wikipedia , lookup
Carbon Pollution Reduction Scheme wikipedia , lookup
Climate change, industry and society wikipedia , lookup
Effects of global warming wikipedia , lookup
Climate change in Canada wikipedia , lookup
Climate change in the United States wikipedia , lookup
Public opinion on global warming wikipedia , lookup
Global warming hiatus wikipedia , lookup
Attribution of recent climate change wikipedia , lookup
Solar radiation management wikipedia , lookup
Global warming wikipedia , lookup
Climate change feedback wikipedia , lookup
Modern Climate Change Darryn Waugh [email protected] OES Summer Course, July 2015 IS THE EARTH’S TEMPERATURE CHANGING? Focus on last 160 yrs Climate over last 160 Years Annual average Temperature (relative to 1961-1990) Surface measurements show clear warming over last 100 yrs. Last decade warmest on record. Climate over last 160 Years Past Climate: Last 2000 years Large uncertainty in temperature before 1850s, but all reconstructions show that global temperatures over last 3040 years have not occurred in at least 2000 years. Spatial Variations in Temperature Trends [IPCC AR5] Although global warming has occurred, this does not mean warming everywhere. More rapid warming over land than oceans. WHAT ARE OTHER CHANGES IN THE CLIMATE SYSTEM? Ocean Heat Content & Sea Level [IPCC AR5] Arctic Sea Ice Land Surface Temp. Tropospheric Temp. Sea Surface Temp. Ocean Heat Content Marine Air Temp. Specific Humidity Sea Level NH Snow Cover Arctic Sea Ice Glacier Mass Balance [IPCC AR5] Reading Material Homework Observed Changes in Climate System [IPCC AR5] WHAT ARE THE CAUSES OF MODERN CLIMATE CHANGE? What has caused for the observed warming over the last 160 yrs? WHAT HAS CAUSED THE RECENT CHANGE IN EARTH’S TEMPERATURE? The suspects: – – – – – Orbital variations Volcanoes Solar Irradiance Internal variability Greenhouse gases WHAT HAS CAUSED THIS CHANGE IN EARTH’S TEMPERATURE? For last 50 yrs The suspects: – – – – – Orbital variations Volcanoes Solar Internal variability Greenhouse gases N N N N Y time scale too long (>10,000 yrs) no sustained forcing (2-3 yrs) no trend since 1960s inconsistent with last 2000 yr record time scale correct + consistent with theory and measurements. Surface Temperature and Solar Variations No trend in solar irradiance in recent decades => Changes in solar irradiance can not explain increase in surface temperature over this period. Greenhouse Effect IPCC, 2007 Absorption by Gases Atmospheric CO2: 1958 to present Mauna Loa South Pole Surface CO2 measurements show long-term increase + annual cycle Atmospheric CO2: 1000 to present Greenhouse Gases (GHGs) Concentrations of CO2, N2O, CH4 (“Greenhouse Gases”) have increased dramatically over last 150 yrs. Temperature and CO2 1000 2000 1st Oil Well Attribution Need to also consider changes in aerosols, clouds and land surface (as well as solar, volcanic eruptions, etc.) for a quantitative understanding of cause of warming. Increases in GHGs has been major contributor to warming. WHAT MIGHT HAPPEN IN THE FUTURE? To make projections of the future climate need 1. Numerical models to integrate together different components and processes, and 2. Projections of future emissions of greenhouse gases (and changes in land use), which depends on human behavior and activities. Climate Models Predicting Future Emissions Future emissions of greenhouse gases (and changes in land use) will depend on several on different factors. E.g. • Global Population trends • World Economic Growth • Source of Energy • Technological Trends • Policies • Historical events (wars, political transitions). All above are affected by human behavior and activities. CO2 Emission Scenarios A1F1 - fossil fuel intensive. A2 - heterogeneous would . A1B - balance between fossil and non-fossil fuels. A1T - large shift to non-fossil fuel. B1 - sustainable development Projections since 2001 [IPCC 2001] Temperature Projections: 2005-2100 High Emissions Low Emissions Temperature Changes: Spatial variations Low Emissions High Emissions Minimum over North Atlantic Ocean and Southern Ocean Warming is largest in NH high latitudes (ice feedback) and larger over land than oceans (heat capacity). Sea Level Rise High Emissions Low Emissions Sea Ice Predictions • All models predict continued retreat of Arctic sea ice. • Some predict complete ice free summers by end of the century. Rainfall Low Emissions High Emissions Less rain in dry regions - Droughts More rain in wet regions - Floods. Heat Stress “Global Climate Change Impacts in the US” Report from US Global Change Research Program http://www.globalchange.gov Impacts separated by Regions and Sectors Impacts of Climate Change “What’s the worst that could happen?” [A rational response to climate change debate] Greg Carven http://www.youtube.com/watch?v=zORv8wwiadQ http://manpollo.org/education/videos/how_it_all_ends/how_it_all_ends.html Areas of Response • Mitigation - reduce the emissions of GHGs that cause climate change. • Geoengineering - manipulate the climate system to offset climate effects of increased GHGs. • Adaptation - adjust human society to changing climate to reduce resulting harms. Geoengineering Stabilization Wedges TAKE-HOME MESSAGES Restatement of IPCC (2013) conclusions: • We know that the climate is warming. • We’re very sure humans are to blame. • The future is hard to predict, but it’s certainly possible that “business as usual” will lead to a catastrophic warming. Contact: Darryn Waugh [email protected] 410-516-8344.