Class Slides: 28

A First for any ESS 112 !!!

Graph shows decrease in Northern Hemisphere snow cover from 1920-2012 Suzanne Jarmusch 94311952 ESS 112 Gives percent decrease in Northern Hemisphere snow cover per decade over 1967-2012 Graph shows decrease in Northern Hemisphere snow cover from 1920-2012 Warming has caused a decrease in snow cover over the past century There is very high confidence that the extent of Northern Hemisphere snow cover has decreased since the mid-20th century (see Figure SPM.3). Northern Hemisphere snow cover extent decreased 1.6 [0.8 to 2.4] % per decade for March and April, and 11.7 [8.8 to 14.6] % per decade for June, over the 1967 to 2012 period. During this period, snow cover extent in the Northern Hemisphere did not show a statistically significant increase in any month. {4.5} AR5 SPM-1 Page 10

Thanushka Fernando ESS 112: AR5 SPM WG 1 “The atmospheric concentrations of carbon dioxide, methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years. Carbon dioxide concentrations have increased by 40% since pre-industrial times, primarily from fossil fuel emissions and secondarily from net land use change emissions.” Concentrations of CO2 (carbon dioxide), CH4 (methane), and N20 (nitrous oxide) have increased by 40%, 150%, and 20% due to human activity. Most CO2 emissions are coming from fossil fuel emissions and cement production which went up to an average of 9.5 GtC yr in 2011. Deforestation is another contributor which has released an average of 180 GtC since 1750. This increase in anthropogenic CO2 has caused ocean acidification. AR5 SPM WG 1 Pages 11-12

These graphs show where CO2 is going and some of the effects. Anthony Pham 72132560 These graphs show where CO2 is going and some of the effects. Atmospheric CO2 concentration has increased since the 1950's. CO2 concentration in the surface of the ocean has also increased since 1990. There is a corresponding decrease in surface ocean pH (ocean acidification). AR5 WG-1 SPM Page 12

This slide is important because: Lynze Cheung ESS 112 – SPM1 This slide is important because: It displays the increasing trend in CO2 and discusses what key CO2 emitters are. It demonstrates one of the negative effect of increased CO2 emissions on the environment (ocean acidification in second graph). but 3) The second graph could have been truncated to remove distracting white space and focus on details of trend. A legend would be helpful instead of having to read figure text for an explanation. -fossil fuel combustion and cement production as well as deforestation and land use changes for co2 emitters -more co2 in atmosphere means more acidic the ocean becomes first graph show more co2 in atmosphere second graph shows the blue which is more partial pressure co2 on ocean surface (concentrations) and lower pH (more acidic) AR5 SPM-1 page 10------12?

Climate warming will be a positive feedback on: Wetlands Tundra Johann Lopez ESS 112 SPM-1 “Emissions of CH4 alone have caused an RF of 0.97 [0.74 to 1.20] W m−2 (see Figure SPM.5). This is much larger than the concentration-based estimate of 0.48 [0.38 to 0.58] W m−2 (unchanged from AR4). This difference in estimates is caused by concentration changes in ozone and stratospheric water vapour due to CH4 emissions and other emissions indirectly affecting CH4. {8.3, 8.5}” “CO₂ is typically painted as the bad boy of greenhouse gases; methane is roughly 30 times more potent as a heat-trapping gas” Efforts to “cut emissions” have mainly been focused at CO₂ while America continues to grow as a CH₄ emitter from: Fracking CAFOs Landfills Climate warming will be a positive feedback on: Wetlands Tundra Strategy to cut CH₄ release March of this year AR5 SPM-1 page 13

Anthropogenic compounds influence RF in different magnitudes Danielle Sison ESS 112-SPM1 This diagram illustrates the RF estimates resulting from anthropogenic compounds. Anthropogenic compounds influence RF in different magnitudes Does not consider role of BVOCs AR5-SPM1 PG 14

Consequences of a warming ocean : Dave Kerr ESS 112-SPM1/ Pg. 8 Consequences of a warming ocean : Higher temperature creates faster reaction times and an increasingly faster rate of acidification Changes in wind and weather patterns, storm creations, and hurricanes

Sundara Bhandaram ESS 112- AR5 SPM1 Climate Stabilization This portion focuses on the key fact that most aspects of climate change will persist for many centuries even if emissions of CO2 stopped. It specifies that there can be large net removal of CO2 from the atmosphere. Problems: It does not specify how much CO2 removal can lower the atmospheric level to a more acceptable level. If there was a target goal this would be able to quantify to policymakers the level of reduction that needs to occur. AR5-SPM1 page 28