Summary

These notes detail various factors influencing climate change, including historic climate trends, and human activities contributing to climate change. Data analysis and graphs illustrate the changes observed, alongside an exploration of possible causes.

Full Transcript

How does climate change? List some factors that effect climate Latitude Altitude/elevation Proximity to oceans Direction of ocean current Surface vegetation Global atmospheric composition Earth orbit How does climate change? Earth’s orbit + amount of solar input Changes in th...

How does climate change? List some factors that effect climate Latitude Altitude/elevation Proximity to oceans Direction of ocean current Surface vegetation Global atmospheric composition Earth orbit How does climate change? Earth’s orbit + amount of solar input Changes in the distance and orientation of Earth relative to the Sun Caused historic climate changes on Earth Ex: periods of glaciation (ice ages) How has the climate changed? Let’s look at some data How has climate changed? Climate change over 450,000 years Climate change over 160 years Compare how climate has changed over time – note the x axis Q: Where have we seen greater fluctuation in average temperatures? How has climate changed? Average annual global temperature over longer time B frame Identify at each axis The arrow show rate of change (temperature change per time/year) Peaks = interglacial periods Lows = ice ages A Rate of change from A – B 12℃ per 9700 years 0.0013 ℃ /yr How has climate changed? Average annual global temperature B Identify at each axis The arrow show rate of change (temperature change per time/year) A Rate of change from A – B 0.6℃ per 30 years (1977 to 2007) 0.02℃/yr How has climate changed? Average annual global temperature B Identify at each axis The arrow show rate of How to interpret this information? The scale of temperature change is muchchange larger in(temperature the change first graph (12℃ vs 0.6℃) but that rate of per time/year) change in the second graph is much high. An order of magnitude higher. A Rate of change from A – B 0.6 C per 30 years (1977 to 2007) 0.02C/yr Climate and CO2 Correlation between temperature change and CO2 levels Think: correlation doesn’t necessarily mean causation Need more data and analysis (in lecture 3 and 4) How has CO2 concentration changed? Source: NOAA How has CO2 concentration changed? Source: NOAA How has CO2 concentration changed? Source: NOAA How have other GHG gases changed? GHG = CO2 , CH4, and N2 All began to increase rapidly about 200 years ago. Evidence from detailed ice core 12 What are the causes of anthropogenetic climate change? (from exceptionally (UNFCCC). unlikely to virtually certain). Where appropriate, findings are also formulated as statements of fact with- 1 out using uncertainty qualifiers. Human and climate change This report includes information relevant to Article 2 of the United Nations Framework Convention on Climate Change SPM 1. Observed Changes and their Causes (UNFCCC). 2 important conclusions based on 1000’s of scientist research studies Humanthinfluence on the climate system is clear, and recent anthropogenic emissions of green- SPM– 1. IPCC 5 gases house Assessment Observed areChanges Report the highestand (2014) theirRecent in history. Causes climate changes have had widespread impacts on human and natural systems. {1} Human influence on the climate system is clear, and recent anthropogenic emissions of green- house gases are the highest in history. Recent climate changes have had widespread impacts on human and natural systems. {1} SPM 1.1 Observed changes in the climate system SPM 1.1 Warming Observed changes of the climateinsystem the climate system and since the 1950s, many of the observed is unequivocal, changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, Warming the climate of the amountssystem of snow isandunequivocal, ice have diminished, and sinceandthe sea 1950s, level hasmany risen.of{1.1} the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, and sea level has risen. {1.1} (from exceptionally (UNFCCC). unlikely to virtually certain). Where appropriate, findings are also formulated as statements of fact with- 1 out using uncertainty qualifiers. Human and climate change This report includes information relevant to Article 2 of the United Nations Framework Convention on Climate Change SPM 1. Observed Changes and their Causes (UNFCCC). 2 important conclusions based on 1000’s of scientist research studies Humanthinfluence on the climate system is clear, and recent anthropogenic emissions of green- SPM– 1. IPCC 5 gases house Assessment Observed areChanges Report the highestand (2014) theirRecent in history. Causes climate changes have had widespread impacts on human and natural systems. {1} Human influence on the climate system is clear, and recent anthropogenic emissions of green- house gases are the highest in history. Recent climate changes have had widespread impacts on human and natural systems. {1} In system SPM 1.1 Observed changes in the climate summary, increases of GHG primarily driven by human activity has results in SPM 1.1 unpresented changes to our climate system Observed changes in the climate system Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, Warming the climate of the amountssystem of snow isandunequivocal, ice have diminished, and sinceandthe sea 1950s, level hasmany risen.of{1.1} the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, and sea level has risen. {1.1} Human and climate change Land use = deforestation Fossil fuel use = coal, oil, natural gas Releases CO2 and other GHG GHG emission by group - IPCC sources Ref: IPCC 5th Assessment; Summary for policy makers Humans + climate change These are the top human activities that increase GHG 1. Fossil Fuel combustion + Industrial processes Contributed to 78% of total GHG emission increase from 1997-2010 40% of total emission post industrial revolution occurred in last 40 years 2. Deforestation + unsustainable agricultural practices Change in land use 3. Urbanization Change in land use: deforestation, decrease in wetlands, conversion of agriculture land Consumption + landfills Urban land cover expected to increase by 56-310% between 2000-2030 What do we know? High scientific certainty Earth is getting warmer, due to increase in GHG due to human activity The change in atmospheric composition is the greatest effect driving Humans responsibility Recorded measurements of the amount of fossils fuels extracted/burned = changes in measured chemistry of atmospheric CO2 Climate models of only natural variation do not explain the temperature changes What do we know? Lower scientific certainty How do clouds respond to warming? How much cooling do reflective droplets and particles in atmosphere offset warming? How often will extreme weather events happen? What will the regional variations of climate change be? How fast will the climate change? How much will the climate change? You will be climate literate Understands at the end of the essential principles of the course Is able to make Earth's climate informed and system responsible decisions with What is regards to actions climate that may affect climate literacy? Knows how to access scientifically credible information about climate Communicates about climate and climate change in a meaningful way Learning Objectives List multiple factors which change climate. Interpret data on a graph Interpret data related to atmospheric CO2 values and average global temp changes. Describe how both have changed over time. Describe how recent average global temperature changes are different from average global temperature changes in the past. Describe 3 human activities that cause climate change.

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