Bio 330 Lecture 16

• pollution
• invasive species
• habitat destruction
• overfishing and species extinctions
• global warming
• ocean acidification

• during the last century and coinciding with the beginning of the industrial revolutoin, the avg temp. on earth have been increasing
• process is speeding up
• no historical records show such a dramatic increase

water vapor and other gases such as CO2, ozone, and methane absorb reflected solar energy and contribute to warmer surface temperatures (60F)

• industrial activities and transportation utilize carbon molecules and release CO2 into the atmosphere
• Levels of atmospheric CO2 are increasing to historical levels

• some scientists have argued that solar cycles are responsible for much of the warming during the 20th century
• some argued that galactic cosmic rays may have contributed to recent warming of the stratosphere
• the observed effect since at least 1060 has been cooling of the stratosphere which one of the predicted of greenhouse gas

El Nino-Southern Oscillation

Pacific Decadal Oscillation

• sea level rises
• potential change in oceanic currents
• albedo reduction
• changes in the chemistry of the ocean and the atmosphere
• changes in the distribution of species

• the sea level has been rising for the last 20k years
• however, the rise has accelerated dramatically during the last century and keeps speeding up

• most of recent sea level rise is due to increase in water temperature and subsequent increase in water volume
• although there has been substantial melting of ice reported, most of the melting affected floating ice, which does not contribute to increase sea levels
• new data from NASA indicates that recent melting of glacier systems is already contributing to sea level rise

• most of recent sea level rise is due to increase in water temperature and subsequent increase in water volume
• although there has been substantial melting of ice reported, most of the melting affected floating ice, which does not contribute to increased sea levels
• new data from NASA indicates that recent melting of glacier systems is already contributing sea level rise

• if land ice sheet covering greenland and antartica melts the sea level can rise up to 200 feet
• entire cities such as new york or miami would be covered with water

• rapid melting of the ice sheet of greenland could potential distrupt or stop the gulf stream
• the timescale is unclear--estimates range from a few decades to a few hundred years

• the extent to which an object reflects light
• the reflectivity of liquid water is very low at high and medium angles
• however, that reflectivity of ice is very high

• increases in global temperatures have the potential to melt the permafrost releasing as much as 70 billion tons of methane into the atmosphere
• huge amounts of methane are accumulated in the deep sea in form of methane-hydrate ice, rise in water temperature may eventually melt it
• we may reach a "tipping" point

• the geographic ranges of most species are limited by climatic factors, including temperature
• any shift in the magnitude or variability of these factors in a given location will impact the organisms living there
• many species are already moving to cooler areas others are changing their life cycle and others will go extinct

• the release of particles to the atmosphere from the use of fossil fuels has created a layer of pollution that reflects sun energy creating a global dimming phenomenom that opposes warming
• the reduction in particle pollution levels and the increase of carbon emissions is increasing global warming