LIFE 103 1st Edition Lecture 21 Outline of Last Lecture I Study techniques II Chapter 35 III Chapter 36 IV Chapter 38 V Chapter 39 VI In class questions I Secondary growth II Meristems III Water potential IV Phytochromes Outline of Current Lecture I Atmospheric CO2 II Greenhouse effect III Evidence for present and future change IV Effects of change Current Lecture Climate Change https www youtube com watch v rE3j RHkqJc I II III Ideas are germs you help them reproduce Thought germs are emotions Anger bypasses your immune system and makes you pass it on like no one else These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute IV V It s really hard to change someone s mind when they are upset They typically argue about each other On becoming famous I II III Scientists get famous by proving other people wrong There is huge incentive to prove that global warming will not happen The IPCC reports are agreed upon by all nations based on the current best science Atmospheric CO2 I II III IV V VI VII VIII IX X There is no doubt that human activities are changing concentrations of CO2 Figure with the monthly average carbon dioxide concentration in Hawaii Looked at patterns Seasons draw the oscillations photosynthesis goes down in Northern hemisphere summer Respiration causes an increase in CO2 in winter Also have Antarctica ice cores from 1000 2000 to look at the CO2 concentrations Concentration of fossil fuels have increased Can tell because carbon 14 levels have decayed Atmospheric CO2 has risen sharply since the industrial revolution began around 1850 Can also look at the global carbon cycle How does the greenhouse effect work I II III IV V VI VII VIII IX X Some gases absorb heat that would otherwise be lost to space Every object with a temperature above absolute zero is emitting photons Heat is motion Objects cool off by emitting photons Objects can also heat up by absorbing key photons The temperature of an object is determined by the balance of photons absorbed vs photons released If you prevent an object from releasing photons the temperature will go up The earth emits photons There is a shortage of photons of specific heat colors that are missing when the earth is observed from space The photons are being absorbed by gases There is strong evidence that the earth is changing I II III Can look at thermometers of the past Weather vs climate I Weather air precipitation patterns for a given moment II Climate long term average As weather changes climate will change IV Can also look at tree rings for records Global circulation models I II III IV V VI VII Keep track of energy and its movement in land oceans and atmosphere Includes feedbacks especially water vapor and greenhouse gases More water vapor will form in the future More clouds will form Coupled with socio economic predictions about how nations will use fossil fuels in coming century Predict the response of the future Scientists have made graphs to predict the future Projected changes to human and natural systems Projected positive impacts I II III IV V Increased timber harvest in well managed forests Increased crop yields in some areas for warming less than 2 degrees Celsius Increased water supply for some areas ex parts of SE Asia Reduced winter mortality at mid and high latitudes Reduced demand for heating energy Projected negative impacts I II III IV V VI Reduced crop yields in tropical and sub tropical systems Reduced crop yield with some variation in most temperate regions Decreased water availability for water poor regions especially sub tropics Increased number of people exposed to water borne ex cholera and vector borne ex malaria diseases Increased deaths from heat stress Widespread increase in flooding due to increased rainfall and sea level increases