A primary pollutants that reacts chemically in the atmosphere
Effects of Photochemical smog
Ozone, 400+ other chemicals
Energy coming in from the sun, some gets through and impacts the earths surface, the green house gasses that are in the atmosphere reflect that heat to the atmosphere and some to the earth
The problem is that more is getting through to earth than is going back out to the atmosphere, it is becoming overly green housed
We can try to mitigate the gases that are causing a problem or try to use them up
The only other option we have is to adapt to the warming weather, when a place gets too hot for humans to live there then we will move away
Effects of Global warming
The trend of global temperatures is warming up
1. CO2 levels will increase and with this increase hurricanes will be fewer, but greater intensity
2. By 2050 if usage of energy and production of greenhouse gases remains the same – we will see deforestation in S. America and Africa, decrease crop production in Africa, intensification of storms in the Gulf of Mexico, and increasing disease in Siberia and Africa due to increase in insect populations and movement of insects, water conflicts around the world
3. Artic Ice mass is decreasing, but rise in sea level is due mainly to the expansion of water due to higher temperatures. Ice masses were created at a time when methane was more abundant, it is now trapped in the ice, if the ice masses melt this methane will be released.
Modeling of climate (temperature) change is done with natural factors, ____ factors, and a combination of the two. Both types of factors are called forcing factors and the combination gives the best “fit” graphs of what we see happening to the climate.
Anthropogenic sources- human made pollution
Greenhouse gasses are
mostly carbon dioxide
many ice caps around the world contain methane, which is 20 times worse than CO2
CO2 (carbon dioxide) is the most important greenhouse gas due to amount that is produced.
Positive feedback loops and negative feedback loops and theri potential effects on warming
Positive feedback loops- warming ice melting, more methane, less reflectance- higher temperature
Negative feedback loops- warming, more evaporation, more clouds, reflection our versus re-radiation down-lower temperatures
Projected effects of global warming on earth's ecosystems
Reduced resilience due to climate, disturbance (wildlife, insects), and global changes in land-use, pollution, fragmentation, exploitation
Terrestrial carbon sequestration peaking mid 21st century
Increased extinction risk for 20-30% of known plants and animals
With temperature increases > 1.5 – 2 C, major changes in ecosystem structure and function due to alteration
of ecosystem interactions and changing biotic distribution
very low precipitation rates and more evaporation than precipitation, very dry, not very diverse compared to other biomes
activites by desert animals and plants to avoid heat and thirst
-plants have very deep roots to get water from deep down; long dormant periods
-lizards, snakes, camels all these animals have very low water requirements; most don’t drink water but get it from their food
Think in forms of agriculture—we can grow food here, but should we?—requires extreme amount of water and energy
great precipitation than desert, but still have droughts; can be extended and severe
-fire was an integral part of how the ecosystems functions
Talk about the Dust bowel poor land use + drought
U.S. Short Grass Prairies—1930’s—Dust Bowl
-drought between 1926 and 1934
-problem: poor farming of marginal land
-during a good year of rainfall, it’s okay to farm these areas; if low rainfall, don’t farm it
-9 million acres lost, 80 million acres damaged
-Farmers moved to cities, but this was during the depression so there were no jobs in the cities
-SCS (Soil Conservation Service) created in 1935 by Congress—try to keep from happening again
Chapparal unique ecosystem between dry and wet climates
is a temperate shrub-land biome found in coastal areas bordering deserts. Proximity to the ocean provides a longer wet season during the winter, which reduces evaporation.
The vegetation is small evergreen shrubs and trees adapted to fire and the thin, low nutrient soil. Fires release nutrients for plant growth and provide heat, which certain seeds require for successful germination. Animals include mule deer, chipmunks, jackrabbits, lizards, and many bird species. People enjoy living in this biome, but find it hard to co-exist with frequent fires and the seasonal lack of water.
Tropical Rain Forest
High biodiversity, poor soils
) are found near the equator, with warm year-round temperatures and heavy daily rainfall. The principle trees are broadleaf evergreen trees, which have leaves year-round and form a dense canopy blocking out sunlight. There is little ground vegetation, with vines adopting a climbing strategy to reach sunlight.
Tropical rain forests have high primary production and incredible biodiversity, covering only 2% of the earth’s surface and containing 50% of the known terrestrial plants and animals. The plants and animals occupy specialized niches in vertical layers based on sunlight needs (Figure 7-7). All dead material decomposes rapidly and is recycled immediately, with very few nutrients stored in the soil. This combination makes tropical rain forests a bad choice for agriculture practices.
At least half of these forests have been destroyed or disturbed by human activities. To maintain earth’s biodiversity and reduce global warming (by CO2 removal) conservation measures must be enacted immediately.
slow tree growth, acidic soils from evergreen needleleaf trees
found south of the artic tundra and have long winters with 6-8 hours of sunlight daily, extreme cold, and short summers with 19 hours of sunlight a day. The major tree type is cone-bearing species (coniferous evergreen trees), such as spruce, fir, and pine. These trees have year-round needle-like leaves that can withstand intense cold and drought. Taiga soils are thin, acidic, and nutrient poor due to slow decomposition.
Mammals include bears, wolves, moose, and burrowing rodents.
What resources and ecosystem services provided by terrestrial ecosystems?
Terrestrial biomes include grasslands, deserts, and forest, which differ primarily because of climate, but are nonetheless connected across the globe. Wind moves heat, moisture, and nutrients around the planet.
For example, phosphate- and iron-rich particles from the Sahara Desert are carried by wind to Brazil, supporting primary production in these tropical rainforests.
Unfortunately, wind can also move pesticides and pollution around the planet; it is estimated that 10% of smog along the U.S. west coast is from China’s industrial air pollution, not something that is likely to subside in the near future.
Human activities affect all parts of the biosphere because everything is connected, which makes conservation a difficult task at best.