SCI 256 – People, Science and the EnvironmentEnvironmental Science Week 1 - Environmental Science, The Scientific Method, and Environmentalism, Human Populations
Tips on the Power Point Presentations… • The Yellow normal text (or yellow, not orange titles) are concepts that are MOST important and are the material that is quizzable/testable. • The presentations (especially those online) are a compilation of previous courses I have taught and are TOO long and detailed for a 5 week lecture run. I will edit (skip by quickly) things that are TOO deep (and will edit those slides out when I next teach. I’m still reducing!)
What a science course is… • Not as much discussion as you are used to. • A lot more PRESENTATION with team • You need input at some point to be able to discuss concepts… • Concepts are encapsulated in terminology. • Learning the terms is very important.
Terminology • Make flash cards • Quiz yourself • Come up with memory tricks (I’ll supply the ones I’ve heard of or the ones in the textbook).
More expectations • We’ll stick very very closely with the textbook • You will be able to go from text to class to (hopefully) the final quiz with everything being reinforced
Repeated Exposure • You will hear the same concepts over and over from different directions. Multiple exposures= hopefully better retention. • The repeated points: • Sources and sinks (pollution) of resources • Energy and the ‘cycling’ resources • What are the major climate issues in the news and why? • Who decides what and how to fix problems? • Cost/Risk Assessment – in all parts of life • Ask questions!
Today • Environmental Science • The Scientific Method (your pre-class paper) • The Development of Environmentalism • Population of the Earth (humans and other things)
Chapter 1 • Our Environment – changes? • Really?
Environmental Science • Don’t be intimidated by the term… we’ll break it down • It is a mixture of many disciplines…which means you only need to get the basics of a wide range of concepts…you can’t (at this stage) dig into the deeper material. • Everything in this section will be repeated and expanded upon in the next 4 weeks.
Breaking it down… • Biology/ecology, geography, chemistry, geology, physics, economics, sociology/demography, cultural anthropology, natural resources management, agriculture, engineering, law, politics, and ethics. • Sounds broad enough? • Sounds fun?
We’ll be concerned with… • Human populations • Natural resources • Pollution – natural and human in origin • air • water • soil
Goals…and the problem… • We need to try to find out how the world really works. • Scientific knowledge is needed, and needs to be reliable, repeatable, complete. • Political decisions often need to be made before science has had time to repeat observations enough for them to become reliable and complete.
Issues. • Which issues are real? • Which issues are the most serious? • Which issues can be addressed? • What will it cost civilization and the global resource pool to address issues? • Is it always ‘gloom and doom’?
The extremes • On a scale of 1 – 10 how do you feel? (Use any # 1 thru 10) • 1: Most if not all the environmental issues brought before the public are extreme, save-the-earth, tree-hugging motivated attacks on our capitalistic economy. • 5: Some environmental issues are wrongly ignored by the population while some environmental issues are over emphasized by the media and policy makers. • 10: Environmental issues are routinely ignored and downplayed by capitalistic interests and attention to corporate profits.
We’ll look at each issue and look for signs of over or under-play in public awareness • Personal observation – some issues are taken beyond the middle ground to overcome societal inertia • There is a need to bend the metal too far the other way to get it to relax to the correct position • We’ll see if this hypothesis holds true.
Environmental Sustainability • A BIG term in environmental science • “It’s the ability to meet humanity’s current needs without compromising the ability of future generations to meet their needs.” • Using resources and earth systems without overusing and/or damaging them.
Environmental Sustainability details • Our actions effect the health and well-being of the natural environment including living things. • Earth’s resources are not in infinite supply – some regenerate (water, wood)- some don’t (coal, oil, metals) • Products we consume always have a cost to the environment associated with them • Everybody needs to play a part for environmental sustainability to be practiced successfully.
Are we operating with sustainability? • Many scientists think we are not: • we use nonrenewable resources for fuel (oil, coal) • we use renewal resources faster than they can be replenished • we put out more toxins (a broad word!) than the environment can absorb/break down in many places. • the number of humans on the planet continues to increase rapidly
So why not reduce the consumption and growth? • Who does it and how much? • How do you enforce it? • Who has the right to dictate the changes and policies? • Society, ecology and economics all matter!
Things need to grow and develop: Sustainable Development • 1992 U.N. Conference on Environment and Development
The components: • Goal: Improve the living conditions of all humans while creating environmental sustainability. • Environmentally Sound Decisions • Economically Viable Decisions • Socially Equitable Decisions QUITE a balancing act! (we’ll see the result of this process as the weeks go by)
Population is on the rise • 1800 = 1 billion world wide • 1930 = 2 billion • 1960 = 3 billion • 1975 = 4 billion • 1987 = 5 billion • 2000 = 6 billion • 2005 = 6.45 billion • 2007 = 6.7 billion • 2012= 7.035 billion
Poverty • High population numbers and poor management of resources leads to poverty. • Defined by the world bank as incomes less than $1/day (one measure of poverty) • Approx. 1.2 billion live at this level • Approx. 2.8 billion are unable to meet basic needs of shelter, food, clothing, education and health. • Approx. 828 million consume than 80% of the recommended daily caloric intake
Flattening out of populations? • We may see it level off by the end of the 21st century at about 7.9 to 10.9 billion.
Consumption – another measure of population + resources • The US consumes more per person (capita) than people in developing countries do. • (We also produce more that is sold and distributed world wide more per capita than any country in the world). • But this means more concentrated energy, resource use and waste/pollution here than elsewhere.
Your first look at pollution and a theorized result… (how it might come home to us) • Pollution: Any alteration of the physical environment that harms the health or survival of any living organisms. • Endocrine Disrupters • There is growing evidence that the direct impact of many chemicals released to the environment from manufacturing and agriculture change the operation of the human endocrine system. • PCB’s and dioxins (chlorine containing chemicals), heavy metals like lead, mercury and pesticides like DDT, kepone, dieldrine, chordane, and endosulfan + some plastic additives like phthalates can all cause our bodies to change chemically (in a broad sense)
Stuff inside – and critical thinking. • The CDC (center for disease control) in 2001 reported elevated levels of 28 different such chemicals/elements in a sample of the civilian U.S. population. In 2012 112 environmental chemicals now followed. • BUT 24 of the 28 chemicals (now 112) had NOT been tested before… they might be naturally picked up from the environment and stored in the body. • The best you can say is we have a baseline now…we don’t know if those have actually increased. • http://www.cdc.gov/exposurereport/pdf/FourthReport_UpdatedTables_Feb2012.pdf
The concern… • Endocrine Disrupters change hormone levels in humans. • SO reproductive development in males and females of various species including humans may be effected. • For example, DDT in Lake Apopka in Florida in 1980 was followed by male alligators having lower testosterone levels • Some cancers are hormonally reactive, so cancer rates may change/increase. • 60 studies since 1938 report sperm counts from approx. 15,000 men. Over time, the counts have decreased 50% from 1940 – 1990 • 2010 update: PCB’s and DDT suspected.
More terms: • When two or more pollutants’ effects add as you expect when you mix them, they are called simply additive. • When two or more pollutants react in a way that causes a stronger hormone change than either would do alone, we call that synergism. (usually bad) • If the result is less than either alone, then it is called antagonism. (usually good) • This hypothesis was not widely accepted until the 1990’s. Environmental problems can arise from surprising combinations of ‘harmless’ chemicals. Even though a chemical is thought safe, it may not be in every situation.
Invasive Species… • What examples have you heard of?
Invasion of the habitat snatchers • Cargo-carrying ocean vessels carry approximately 79 million tons of ballast water containing foreign clams, mussels, worms, small fish, crabs and microscopic aquatic organisms. • The jellyfish-like organism called a comb jelly hit the Black Sea. With much food and no natural predators, it underwent explosive growth. • Fishing industries have been almost eliminated due to the die-off of native fish populations.
Here at home: • The Zebra mussel from the Caspian Sea hit the Great Lakes in the mid 1980’s. • It clusters on all objects in the water (buoys, boats, and water intake systems). • Now has invaded the Mississippi River • Costs the US about $5 billion to control and in economic losses
Other examples? • Rabbits in Australia (then foxes, then the myxomatosis virus – 90% initially, 75% now)
And… • Kudzu in the Southern US (1876) • Mosquitoes with West Nile virus – eastern US – 1999, 46 states in 2003, all states by 2010 • Wild/feral cats • Weeds: (bermuda grass) in the desert southwest (Georgia in the 1800, spread west during the Gold Rush – 1850’s) • http://www.fws.gov/invasives/
Overview Time… • We’ll spend more time repeating these BIG issues in the next 3 weeks. • (I’m repeating that I’ll be repeating.)
Onto higher topics… Ozone • Stratospheric Ozone • Found in a layer of the atmosphere from 6.2-28 miles up • Formed by ultraviolet rays from the sun breaking down O2 (diatomic oxygen – what you breath) • Shields us, likewise, from this UV light • Protection from sunburns, skin cancer, plant mutations
The hole truth • Thinning NOT a hole • Hypnotized to be caused by chlorofluorocarbons (CFC’s) • First observed in 1985 over Antarctica • Happens Sept/Oct every year – Spring in the southern hemisphere • 1990 amounts of ozone were 50% lower than 1980 amounts. • 1992 some thinning observed over the Arctic
The culprit • CFC’s = a chlorine source a catalyst • Noclilucent clouds • Colder temperatures up there • From Global Warming? (more heat near the earth surface, less aloft) • 1987 – 160 countries cut back on CFC production/use. • CFC’s can last (a catalyst is not consumed) for 120 years+ • More on this later.
CO2 and Global Climate Warming • A hot topic. (sorry) • More like a thermal blanket than a greenhouse (The Thermal Blanket Effect would be a better name, but Greenhouse stuck). • The atmosphere is transparent to visible light (so we can see stars and the sun) • It is NOT as transparent to infrared light – the way the earth cools itself. CO2 would look like a haze if you ‘saw’ with infrared eyes.
Warming up • So the theory is that more CO2 = more infrared that SHOULD go to space stays down near the earth’s surface. We warm up down here.
Sources- it matters! • Burning forests/grasses = releases CO2 BUT growing trees/leaves/grass consume CO2 • NOT a source of greenhouse warming • Oil/coal = LONG TERM carbon storage – it’s CO2 that hasn’t been up here in a LONG time • This means a new balance needs to be set…