Human Impact on the Biosphere

Human Impact on the Biosphere

Acid Precipitation • Acid precipitation, acid rain, is when the pH of precipitation is much lower than normal rain • Normal rain is mildly acidic at 5.6 • Acid rain has be measured as low as 2 which is almost 10,000 more acidic that normal rain • When nitrous and sulfur oxides produced from burning fossil fuels mix with water in the atmosphere, nitric or sulfuric acid is produced

Acid Precipitation • Acid precipitation occurs in industrialized parts of the world or down wind of these regions as the pollutants can travel long distances • Acid rain and damage building, plants and change the chemistry of bodies of water • Long term changes can damage soil and bodies of water making unable to sustain life

Acid Precipitation • Reducing industrial and automobile emissions, would lead to less air pollution and decreased acid rain • Burning coal is the primary source of sulfur oxide entering the atmosphere, so finding alternative energy sources is a great direction

Climate Change • Climate change is a normal part of the patterns of the earth, alternating between ice ages and warnings • Sea levels have risen and dropped over the past 4.54 billion years

Climate Change • Much evidence shows that we are currently in a warming cycle, but the concern is that since the industrial age, humans may be accelerating this change • Large amounts of Greenhouse gasses are being generated by human activity such as carbon dioxide and methane, which makes the planet’s overall average temperatures warmer

Climate Change • Rising sea levels and change in ocean currents can flood densely populated regions of the world since the largest percent of the human population live on or near the coast • Even if our measurably high levels of greenhouse gases are not the cause, reduction of burning fossil fuels and ways to capture methane waste from cattle can possibly slow down these changes

Ozone Layer Depletion • The ozone layer is in the stratosphere and protects us from ultraviolet (UV) radiation that can cause mutations and directly damage plants and other living organisms • Without the ozone layer life as we know it would not exist

Ozone Layer Depletion • The use of chlorofluorocarbons (CFCs) as propellants and coolants damaged this protective layer and caused it to thin and created a large hole over Antarctica • This has caused higher rates of skin cancer and damage to crops • Continued loss of crops could increase famine and extinction rates on earth

Ozone Layer Depletion • The Montreal Protocol enacting in 1987 asked for a voluntary and systematic ban on ozone damaging chemicals and some recovery of the ozone layer has already been observed • The atmospheric levels of CFCs have also started decreasing since the ban

Invasive Species • Also called alien, nonnative and introduced species • These are species either accidently or intentionally released into a nonnative habitat and were more successful than native species (remember the competitive exclusion principle) • They can reduce biodiversity in an area • Kudzu, fire ants and tiger mosquitoes are a few examples

Invasive Species • Invasive species are a problem all over the world were people are or have been • They replace native species and can lead to extinctions • Some species can even significantly change the local ecosystem • Identify accidental introductions like ballast water and infected plant material • Do not allow nonnative species to be sold as pets

Use of Fossil Fuels • The three types of fossil fuel are coal, natural gas and petroleum (oil) • These carbon rich substances are also rich in high grade energy, but were underground and not a active in the carbon cycle on the planet's surface • Burning fossil fuels produces large amounts of air pollution including carbon dioxide, carbon monoxide, nitrous oxides, sulfur oxides, lead, mercury, ozone (ground level=bad) and more

Use of Fossil Fuels • Burning of fossil fuels occurs in factories, most forms of transportation, farms, for generation of electricity and heating. Petroleum is used in 100,000s of products from foam cups to pesticides. • Air pollution leads to many human health problems, acid rain, water pollution and habitat destruction. Plus, biomagnification of lead and mercury up the food chain.

Use of Fossil Fuels • Alternative sources of energy • Substitution for petroleum in the manufacture of many products • Reduction of wasteful packaging materials and recycling of plastics can help reduce our carbon footprint

Overfishing • 1 billion of the world’s population depends on fish/seafood as their only source of protein and main source of food • Increased use of technology has caused near extinction of many important species of fish like cod • Currently, fishing continues unsustainably meaning more fish are caught that can replace themselves

Overfishing • Widespread loss of these consumers can devastate marine and freshwater biomes • Human populations will have to seek of sources of food • Enforcing fishing regulations and high quality aquaculture can take some of the stress off of wild populations allowing them to recover

Deforestation • The clearing of forests on a huge scale • At the current rate, the rain forests of the world will be gone in 100 years • Forests are cleared for wood (including fuel wood and for paper), human population spread, and agriculture • Forests are decreasing globally, but the rain forest are the most threatened

Deforestation • The rain forests are huge sources of biodiversity and their loss could prevent discoveries of foods or medicines that would help the human population • Continued loss means that large amounts of carbon dioxide will not be removed from the atmosphere and less oxygen produced. Extinctions of forest dwelling organisms and all of the other natural services that forests provide would be decreased or loss • Better management of forests and protection of key habitats has to happen to enact change

Desertification • Desertification is the degradation of formerly productive land into a desert • Grasslands are the most sensitive, but climate change, overgrazing of cattle, redirection of rivers by damming and poorly managed farming and irrigation techniques can cause these changes to any ecosystem (the dust bowl?) • Deserts do not have the biodiversity and productivity of other biomes

Desertification • The loss of arable land and local biodiversity can be devastating for the human population and the organisms • Extinctions and further land loss can result for these environmental changes • Good irrigation techniques and the use of area appropriate crops can prevent desertification as well as employing soil protection regulations

Habitat Loss • Habitat loss/degradation/destruction is the changing is an environment so it is no longer suitable for the native organisms • Environments change naturally, (remember succession?), but humans can change areas quickly by building, polluting and agriculture • Even small environmental changes can cause the loss of some of the native species

Habitat Loss • Habitat loss/degradation/destruction can then lead to significant loss of productivity and loss of those primary producers always causes losses up the food chain • Without proper management of environments, especially highly productive areas like estuaries and rain forests can be lost • The human population has to remember that we are part of nature and should be steward of the earth as even renewable resources must ne used sustainably..

DDT Use In 1950's The World Health Organization (WHO) financed and supported the first ever team of over 14,000 parachuting cats into Borneo. It was early in the 1950's, the Dayak people of Borneo tragically suffered an outbreak of malaria, spread by mosquitoes. The World Health Organization (WHO), without thinking through all the consequences, liberally sprayed the area with DDT to kill the mosquitoes. The mosquitoes died, malaria lessened and the people of Borneo were happy. Then roofs started to collapse and the people of Borneo were sad. It appeared that a parasitic wasp had previously been keeping a thatch-eating caterpillar under control and the DDT killed the wasps, meaning the caterpillars were having a field day. Tragically various poisoned insects were eaten by geckoes, which were eaten by cats and many cats died. The people of Borneo missed their cats greatly and asked WHO to help repair the damage it had done. WHO talked to some of their feline experts who proposed that 14,000 cats should sky dive into Borneo, in order to help the grieving residents, who longed to have their feline company once more. WHO also thought it might help with the massive outbreak of rats, which were spreading typhus and plague. WHO initiated Operation Cat Drop and the cats started parachuting. Then the rat population declined and the people of Borneo were happy once more.

Water Pollution & Eutrophication • Pollution he degrading of water quality and eutrophication is the when excess nutrients enter bodies of water causing rapid growth of plants or algae • Runoff of animal waste and or fertilizers accelerate eutrophication and can lead to toxic algal blooms causing fish kills and impacting human health

Water Pollution & Eutrophication • Pollution and eutrophication can devastate the aquatic and local terrestrial environment leading to water unfit for use by most organisms except for some detritivores and decomposers • Continues mismanagement of water can lead to further unavailability of water to our growing population • Education and better management to protect our limited water supply is essential

Human Impact on the Biosphere