Carbon Cycle and Climate Change PDF

# Carbon Cycle and Climate Change ## Carbon Cycle - **Starts with carbon cycle:** - **Carbon cycle buckets:** - Oceans - Land biosphere - Atmosphere - **How carbon in atmosphere:** - Exhale - Burn fossil fuels - Livestock - Volcano - **How carbon out:**...

# Carbon Cycle and Climate Change ## Carbon Cycle - **Starts with carbon cycle:** - **Carbon cycle buckets:** - Oceans - Land biosphere - Atmosphere - **How carbon in atmosphere:** - Exhale - Burn fossil fuels - Livestock - Volcano - **How carbon out:** - Plants - Dissolves in ocean - **Carbon into living things:** - Cellular respiration - **Carbon in ocean:** - Dissolves - **Emission of CD lead to beat:** - CD are higher now - Added CD make the world get warmer - As long as the CD level is higher than the industrial base level the world will continue to warm. - Even if emission input stopped temp would still rise - Using models to predict climate change - Concentration pathways of CD - The numbers - CD would cause mean radiative forcing - Socio economic pathway - Story lines, actions we take - Different futures how they effect all CD - Things that directly effect - Different ways we could handle Pop / GDP - Math / Numbers ## Climate Change - **There is no difference between the 5 pathways for the first 10 years because change takes time.** - **1.5° is not a goal we can stay below, but...** - **Impact** - Going up - Population is going up - Affluence is going up (standard of living continually increases) - Technology impact on emissions, brings it down - Carbon intensity - Energy intensity - **Heating is uneven.** - **The Arctic is heating the most** - **Cause of CC in the past and future:** - Strength of the sun. - No, - Volcanic activity - No, cooling effect - Orbital changes - No, too slow - Greenhouse gasses - Yes, it traps the heat in the atmosphere and acts relatively fast - Water vapor feedback - Yes - **Impacts of CC** - Worse near the Gulf of Mexico / Southern U.S. - Because of sea level rise (flooding, loss of infrastructure, salt water intrusion, severe droughts) - Tourism - Habitat loss ## Effects of Climate Change - **Direct and indirect effects of CC:** - Ocean acidification - Carbon is added to the atmosphere, then dissolves in ocean - Coral bleaching - Ocean temp changes (too warm) - Bigger crops - Increase in CD - Less water / less energy produced by hydroelectric farms - Rain is falling in unusual places - An effect US would face if an artic ice sheet melts - Increase sea level - **Organizations taking CC seriously:** - Oil and gas companies - Lots of people with good quality information - Military - Stock trading companies - **What does an exponential graph increase greatly?** - Because it multiples by what's already there. - Climate change exponential growth: - Water vapor feedback - Temperature - Population - GDP - Diseases - **Social cost of carbon** - Interest rate (rate of growth) - Carbon can cost farmers their jobs when they can no longer grow that crop - The impact of CC affects society in webs. ## Understanding Climate Change - **Radiative forcing:** - Changes that alter the energy absorbed or emitted by the Earth and its atmosphere - The amount that the energy balance is disrupted by a change in a climate input: - A change in Earth's energy balance: Energy in - Energy out - Positive forcing example: Decrease in atmospheric aerosols - Positive feedback example: If a radiative forcing decreases energy coming into the Earth, a positive feedback would result in... - A temp decrease - Ice-albedo effect is a feedback - CO2 and methane and equally emitted and absorbed without human activity - Raising livestock increases the amount of methane in the atmosphere - Carbon dioxide - Natural contributions to the atmosphere are much larger than human inputs - Lasts a much longer time in the atmosphere - Methane - More powerful greenhouse gas - We know that volcanoes are not responsible for carbon dioxide increase by measuring the amounts of carbon 12 and carbon-13 isotopes in atmospheric carbon dioxide - We don't know if there is a limit CD in the biosphere and ocean can remove - Temperature variations on a scale of decades: - Internal unforced variability - Changes in the Earth's orbit - Changes in greenhouse gasses - Natural cycles are not a cause of climate change because... - There is not a physical mechanism that explains how these natural cycles could be causing the warming. ## Modelling Climate Change - Scientists have not been able to simulate a climate model in which natural cycles cause overall warming - There is no evidence that these cycles have caused past climates to warm or cool outside of the ups and downs within the cycle - Scientists don't attribute modern global warming to changes in solar radiation because they have observed and measured changes that are either too long-term or cyclical - Ways continental drift can cause climate change: - Continents located where ice sheets can form - Blocking or allowing North / South ocean currents - Exposing new rock to weathering. - Human greenhouse gas emissions are responsible for modern global warming because it is unequivocal that humans have increased greenhouse gas concentrations and warmed the atmosphere - Factors that influence human greenhouse gases and aerosol emissions: - GDP - Population - The major differences in climate forecasts: - Changes in greenhouse gas emissions - Representative Concentration Pathways (RCP): Predicted radiative forcing in 2100 - Shared Socioeconomic Pathways (SSP): Choices that humans make regarding society and development - Biggest inaccuracy in how climate models predict the future climate.. - They don't show realistic year to year variability - What helps to decrease "IPAT": - Switching from fossil fuels to renewable energy sources - Using more energy efficient machines and processes