EESA11 Week 1 - EESA11 Environmental Pollution Thursday Week 1 Introduction Understanding Pollution 1 Humans are massively changing the Earth

EESA11 Week 1 - EESA11 Environmental Pollution...

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EESA11 Environmental Pollution Thursday, January 10, 2019 Week 1: Introduction + Understanding Pollution 1. Humans are massively changing the Earth - Between one-third and one-half of the land surface has been transformed by human action. - We are the major reason for all of these troubles… o In the 50’s-60’s this is when we saw the impact of humans on the environment. o Lots of jobs, lots of studies came from the study of environmental pollution/studies. - Some plants but not all can fix nitrogen… (nitrogen fixation) o Nitrogen through the roots into the atmosphere. - The carbon dioxide concentration in the atmosphere has increased by nearly 30% since the beginning of the industrial revolution. - More than half of all accessible surface fresh water is put to use by humanity. - More atmospheric nitrogen is now fixed by humanity than by all-natural terrestrial sources combined. - About one-quarter of the bird species on Earth have been driven to extinction. - All trace to a single cause, the growing scale of the human enterprise. The rates, scales, kinds, and combinations of changes occurring now are fundamentally different from those at any other time in history; we are changing earth more rapidly than we are understanding it. (Vitousek et al. 1997) 2. Biosphere 2: The Experiment (i) Objective - To test if and how people could live and work in a closed biosphere, while carrying out scientific experiments. - It was designed to explore the web of interactions within life systems in a structure with different areas based on various biological biomes. - To explore the possible use of closed biospheres in space colonization. (ii) Key issues - Oxygen levels began falling at a steady pace of 0.5% per month. This trend continued to the point where the atmosphere inside resembled that of a community at an elevation of over 1200 m. - Atmospheric carbon dioxide spiked erratically, while nitrous oxide rose to levels that could impair brain function. (air) - Water became polluted. - Several plant and animal species became extinct.
(iii) A pessimistic conclusion - Earth is a closed system too, a larger version of biosphere 2! (iv) Ten lessons from biosphere 2 - #1 Ecology can be a science : no one had ever tried to do ecology in what is essentially a giant test tube, with full control of every variable. Biosphere made complex natural systems more like chemistry and physics – something researchers could experiment on instead of just observe. - #2 Coral reefs are salvageable : marine biologist Gaie Alling oversaw the artificial reef- the largest ever constructed – in the projects million-gallon ocean. - #3 Complexity is no obstacle : the system balanced itself remarkably well. - #4 Massive spacecraft WILL hold their air : largest sealed structures ever built, and overall air leakage rate was less than 10% per year.

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