APES CH.19
Urgent priority
Is to do all we can to avoid any and all estimated climate change tipping points
One characteristic of any chemical that determines whether or not it should be classified as a pollutant
It's concentration in the atmosphere
Climate scientist do not expect aerosols and soot pollutants to counteract and enHance projector climate change very much in the next 50 years for two reasons
1. Aerosols and soot fall back to the earth or wash out of the lower atmosphere within weeks or months 2. Aerosol and soot inputs into the lower atmosphere are being reduced because of their harmful impacts on plants and human health
Four major prevention strategies
1. Improve energy efficiency to reduce fossil fuel use, especially the use of coal 2. Shipped from carbon-based fossil fuel's to low carbon renewable energy resources based on local and regional availability 3. Stop cutting down tropical forest and plant trees to help remove more CO2 from the atmosphere 4. Shift to more sustainable and climate friendly agriculture
A growing number of analyst are contending that the approach by itself will not work because
1. Psychological research indicates that using fearing to go to promote sacrifice to change behavior rarely works 2. People are primarily interested in the short term, not long term, benefits of changing their behavior 3. For elected officials, spending their efforts on long-term problems is most often not in their best short term political interest in getting elected
Methane
70% of methane emissions are the result of human activities, including livestock production, rice production, natural gas production, mines, landfills, in the flooding of land behind large dams. Methane levels in the atmosphere have tripled. Methane remains in the atmosphere for about 12 years and each molecule of messing has 25 times the amount of warming potential of them all cure of carbon dioxide, levels are expected to rise in the future if the atmosphere warms as predicted and melt some of the permafrost in the arctic tundra and in the Arctic's ocean sea bed, there are surprising levels of methane being released through cracks in floating Arctic ice
What makes the current problem urgent
A rapid projected increase in the average temperature of the lower atmosphere during this century
Greenhouse gases
About 1% of the earths lower atmosphere, primarily water vapor carbon dioxide, methane, and nitrous oxide. Heat radiated into the atmosphere by the earth causes molecules of these gases to vibrate and release infrared radiation with longer wavelengths into the lower atmosphere. As this radiation interacts with molecules in the air, increases their Kinetic energy and warms the earths surface
Oceans
Absorb CO2 from the atmosphere as part of the carbon cycle and the help to moderate the Earth's average surface temperature and its climate. Estimated that oceans remove roughly a third of carbon dioxide pumped into the lower atmosphere by human activities, oceans also absorb heat. Ocean current slowly transfer some of the carbon dioxide to the deep ocean, where it is buried in carbon compounds and bottom sentiments for several hundred million years. Ability of the oceans to absorb CO2 decreases as water temperature rises as the oceans warm up, some of their dissolved CO2 is released into the lower atmosphere, like CO2 bubbling out of carbonated soft drinks. As oceans become warmer they become more acidic , can have a harmful effect on marine ecosystems
Water vapor
Accounts for about 66% of the earth's greenhouse effect, as the air warms, any given volume of air can hold more water vapor. Just the warming affect of other greenhouse gases can lead to a higher level of water vapor, which in turn amplifies the greenhouse effect.
Clouds
An increase in sick and continuous cumulus clouds at low altitude could decrease service warming by reflecting more sunlight back into space. But an increase in thin, wispy serous clouds at high altitudes could cause more warming of the lower atmosphere by preventing some heat from escaping into space
Droughts
As they become worse in more widespread, the growth of trees and other plants in some areas has declined, which has reduce the removal of CO2 from the atmosphere. Soil in some areas is dried out, making surface temperatures hotter, wildfires will also become more common, and this add CO2 to the atmosphere
Human activities that lead to a significant increase in the levels of greenhouse gases in the lower atmosphere
Burning of fossil fuels, Deforestation , and agriculture
One way to measure CO2 emissions
By their total global weight (gigatons )
Aerosols
Can hinder or enhance both the greenhouse warming effect and cloud formation, depending on factors such as size and reflectivity. Most aerosols, such as light colored Sulfate particles produced by fossil fuel combustion, tend to reflect incoming sunlight and cool the lower atmosphere
Weather
Consists of short-term changes in atmospheric variables such as temperature, precipitation, when, barometric pressure in a given area over a period of days or hours
Positive feedback loops
Cycles of change that cause systems to change further in a certain direction. Important example of such a loop is the accelerating melting of Arctic ice, which causes further warming, which in turn, speeds the melting.
Climate
Determined by the average weather conditions of the earth or of a particular area, especially precipitation and temperature, over a period of at least three decades to thousands of years
Intergovernmental panel on climate change
Document past climate changes and project future changes, includes more than 2500 climate scientist and scientists and disciplines relating to climate studies for more than 130 countries
What climate models indicate in worst case scenarios
Floods in low-lying coastal cities, vast wildfires, grasslands turning into dust bowls, rivers drying up, ecosystems collapsing, extinction of up to half of the world species, more intense and longer lasting heat waves, more distractive storms and flooding, and rapid spread of some infectious tropical diseases
Output, clean up strategies
Focus on dealing with CO2 after it has been produced, many analyst argue that rather than spending huge amounts of time and resources on such strategies, we should focus on reducing and preventing CO2 emissions
Earths climate also affected by
Global air circulation, large areas of ice that reflect incoming solar energy and help cool the atmosphere, making concentrations of different gases that make up the atmosphere, occasional slight changes in ocean currents, average temperature and precipitation are two main factors affecting global, regional, and local climates, but temperature is the key variable that climate specialist watch
Output strategies
Global treeplanting program, restore wetlands, plant large areas of degraded land with fast growing perennial plants, use of bio char, and help restore natural forests
Technology transfer
Governments of more developed countries could help to fund the transfer of latest green technologies to less developed countries so that they could bypass older, energy innovation and polluting technologies.
Soot
Has the opposite effect Spot emitted into the air by coal burning power and industrial plants, diesel exhaust, open cooking fires, and is burning forests has a warming affect others four times greater then was estimated earlier.
Nitrous oxide
Levels have risen about 20% during the greenhouse gas emissions from human activities, but it remains in the atmosphere for 114 years and each molecule N2O has nearly 300 times the warming potential of CO2. Fertilizers and other sources of nitrogen have greatly increased nitrogen inputs into the environment
Climate scientists
Look at data on the normally fluctuating weather conditions of a particular area of the earth to see if there has been a general rise or fall In any measurements such as average temperature or precipitation over a period of at least 30 years determine whether and how the climate of an area has changed
Two approaches to dealing with the projected harmful affects of global climate disruption
Mitigation and adaptation
Put a price on carbon emissions
One way to do this is to phase in carbon taxes or fees on each unit of CO2 or CH for emitted by fossil fuel use, or to levy energy taxes or fees on each unit of fossil fuel that is burned. Loring taxes on income, wages, and profits to offset such taxes could help to make such a strategy more politically acceptable, and it might also stimulate the economy.
Concentration of carbon dioxide
Plays an important role in determining the average temperature of the atmosphere. Measurements of CO2 in bubbles at various steps in ancient glacial ice indicate that changes in levels of these gases in the lower atmosphere have correlated barely closely with changes in the global average temperature near the earths surface during the past 400,000 years
Greenhouse effect
Please a key role in determining the earths climate, occurs when some of the solar energy absorbed by the earth radiates into the atmosphere as infrared radiation at various wavelengths
Loss of biodiversity
Primary cause of extinction would be loss of habitat
Glacial and interglacial periods
Prolonged periods of global cooling and global warming
How scientists analyze different types of evidence
Radio isotopes in rocks and fossils, plankton and radio isotopes in ocean sediments, tiny bubbles, layers of sediment, and other materials trapped in different layers of ancient air found in ice cores from glaciers, pollen from the bottom of lakes and Boggs, tree rings, and temperature measures taken regularly since 1861. Temperature measurements now include data from more than 40,000 measuring stations around the world Measurements have some limitations, but they showed general changes in atmospheric temperature, which in turn can affect the earth's climate
Carbon capture storage
Remove CO2 from smoke stacks of call burning power and industrial plants and to store it somewhere
Kyoto protocol
Required to 36 participating countries that are developed to cut through emissions of CO2, ch4, and N2o to certain levels by 2012, when the treaty was to expire. Less developed countries were excluded from this requirement, because such reductions could Curb their economic growth
Solar output
Rise in global average atmospheric temperatures could not be the result of increased or output. Instead they determined that the energy output of the sun has dropped slightly during the past several decades. The troposphere has warmed while the stratosphere has cooled. Opposite of what a hotter son would do
What is the problem
That we do not know how close we are to such tipping points, although there are no indications that we will cross any of them in the immediate future.
Carbon footprint
The amount of CO2 generated directly and indirectly by anyone person or group. An important aspect of your carbon footprint is your diet, and non-food purchases of calm and good such as clothing and electronic devices
Characteristics of this complex problem that make it difficult to tackle
The problem is global The problem is a long term political issue The projected harmful and beneficial impacts of climate disruption are not spread evenly Many propose solutions, such as sharply reducing or phasing out the use of fossil feels, are controversial Some social scientist contend that humans are not hardwired to respond to launch and threats
Ocean acidification
The process by which much of CO2 absorbed by the ocean reacts with water to produce carbonic acid. Hire acidity threatens marine life because it hinders their ability to build and repair structures. Increased acidity has been shown to decrease populations of phytoplankton that are the primary producer species of ocean food webs in that also remove CO2 from the atmosphere
One major problem with most of these technological fixes and with some carbon capture and storage schemes
They require huge investments of energy and materials, and there is no guarantee that they will work
Climate change tipping points
Those thresholds beyond which natural systems could change for hundreds of thousands of years, with possible catastrophic effects. Example of this is atmospheric CO2 levels, we need to prevent CO2 levels from exceeding 450 ppm, another example is global average atmospheric temperature which we can no longer avoid a global temperature rise of more than 2°C
Mitigation
To act to slower and to avoid climate change tipping points
Cap and trade, or pollution reduction approach
To place a cap on total human generated CO2 and CH emissions in a country or region, issue permits to emit these pollutants, and then let polluters trade these permits in the marketplace
Adaptation
To recognize that some climate change is unavoidable and to try to reduce some of its harmful effects
One approach to promoting the preventative solutions listed
To strictly regulate carbon dioxide and methane as air pollutants
Geoengineering
Trying to manipulate certain natural conditions to help counter an enhanced greenhouse effect
Factors that have altered the climate of the planet
Volcanic emissions, changes in solar input, the shifting of tectonic plates, and impacts by meteors and astroids