Topic 4 - Environment. Conditions for life

Transcription

1 Topic 4 - Environment Conditions for life

2 Body Core Temperature Temperature of internal organs (liver, heart, intestines) Human core temperature: 37.5 o C Regulation of body core temperature Radiation: heat lost directly through skin Perspiration: evaporation cools body

3 Body Core Hyperthermia 40 o C (104 o F) dysfunction of temperature regulating system dehydration, blood pressure drop (dizziness) 41 o C (106 o F) cessation of enzyme function unconsciousness, coma, death Hypothermia 35 o C (95 o F) clumsiness, forgetfulness, slurring of speech 32 o C (90 o F) uncontrollable shivering, tremors, accelerated heartbeat and breathing 28 o C (80 o F) major organ failure, brain damage, death

4 Mercury 333 F Venus 867 F Earth 59 F Mars -81 F Jupiter -162 F Saturn -218 F Uranus -320 F Neptune -320 F

5 Earth s Astronomical Position Life as we know it exists in only 1 place Narrow temperature range (Goldilocks Zone) 100 million miles from the sun 1 million miles closer - water vapor only 1 million miles farther ice only What controls our climate?

6 Milankovitch Theory Milutin Milankovitch 1938 Shape of Earth s orbit around sun (Eccentricity) Tilt of its axis of rotation (23.5 o ) Wobble during rotation (Precession)

7 Other factors: Earth s Climate Ozone layer (protects from UV radiation) Clouds (reflect and absorb sunlight) Oceans (distribute heat) Topography (shape of the land) dry rain rain shadow AAAAAAAAA5g/XHdQqgqCbUw/DSCN2202.JPG

8 Earth s Environments Relevance to organisms Lithosphere: soil, rocks, substrate Hydrosphere: contains water 97% oceans, 2% ice caps, 1% fresh Atmosphere: contains important gases, protection from ultraviolet rays Biosphere: biomass (Organism section)

9 Lithosphere From the upper most layer of the mantle to the crust Thickness Soil 1 mile in mid-ocean ridges 80 miles beneath older ocean crusts 93 miles at continental plates Particles from Earth s crust (from weathering) Organic materials lithosphere/tectonics/earth_structure.jpg

10 Contamination of the Hydrosphere Nitrogen: used in agriculture (below) carried into water systems excess nitrogen: China: 200 lbs per acre Eutrophication: enrichment of water by nutrients, bacteria increase, oxygen depletion

11 Death in the Gulf of Mexico Hypoxia: lack of O 2 Aquatic life suffocates 2012: 6,700 square miles Other effects of nitrogen? When mixed with water vapor, nitrogen leads to acid rain (kills plants, acidifies freshwater, damages structures)

12 Atmosphere Excelsior Project: 1 st man in space (1959) Joe Kittinger: 103,000 feet (20 miles) Recently: Feliz Baumgarrner (2013) 128,000 feet (24 miles)

13 Atmosphere Composition 78% Nitrogen 21% Oxygen 1% Others: CO 2, Argon, Neon, Helium, Methane, Ozone Green house gases Water vapor 60% Carbon dioxide 26% Others: Methane, Nitrous oxide, Ozone

14 Greenhouse Effect CO 2 acts like a glass in a greenhouse - allows: solar radiation pass to the Earth - prevents: loss of reflected heat into space CO 2 stored in many forms (one is fossil fuels) Too much CO 2 in atmosphere = too much heat CO 2 rise is best current hypothesis for increasing temperature (well supported by data) (Climate change)

15 Climate change Weather: the state of the atmosphere at a place at one time (heat, humidity, precipitation, wind) Climate: the weather conditions prevailing in an area over time

16 Effects of climate change Common sense? Global warming Global wierding Predictions Uncertainty in weather 16 Jan 2014 BBC News Melbourne, where the tournament is held, is seeing a third consecutive day of heat above 40C, with temperatures of 41.7C (107F) on Thursday. Australia's Climate Council says in a report that the number of hot days in the country has "more than doubled" was recently declared Australia's hottest year on record.

17 Climate change Arguments: The Earth is warming up The cause is man-made

18 Warming Earth increase of 0.80 C worldwide 9-10 of the warmest years have occurred in the last 14 years Odds? 1:10,000 chance getting 14 heads in a row with a coin flip Decades 2000s 1990s 1980s

19 Warming Earth Arguments: The Earth is warming up Data: Temperature data sources: Tree ring, corals, ice cores > 20,000 observational data sets shown increase Earlier breeding, melting of permafrost, changing migration Mann et al. 2008

20 Warming Earth Sap and Maple trees (23.3 in text) Cherry trees in Washington, D.C. Blooming linked to spring temperature : April 5 th : April 3 rd : March 31 st

21 Climate change Arguments: The Earth is warming up The cause is man-made

22 CO 2 and Temperature over the last 400,000 years, tight correlation

23 The cause is man-made CO 2 and temperature are tightly correlated Rise in both over the past 150 years Experiments and models and CO 2 show relationship Venus! 867 F, mostly due to greenhouse effect (atmosphere is 98% CO 2 ) What evidence is there against climate change? No scientific evidence What arguments do people use against climate change?

24 Arguments Trend shows global COOLING example: World wide temperatures decreased from 1998 to 2005 Climate is complex, but long term data reveal trends data averaging remove year to year variation

25 Arguments This change is within natural variation of the Earth. Current trend is above the average for the last 1000 years

26 Arguments It s not humans, it s the Sun! Sun intensity has created the rise in temperatures. Sun intensity has declined as temperature have risen Figure 1: Annual global temperature change (thin light red) with 11 year moving average of temperature (thick dark red). Temperature from NASA GISS. Annual Total Solar Irradiance (thin light blue) with 11 year moving average of TSI (thick dark blue). TSI from 1880 to 1978 from Solanki. TSI from 1979 to 2009 from PMOD.

27 Spread of West Nile Virus First discovered in New York in 1999 Now occurs across the US (2012, 286 people in US died) Change in temperatures may have facilitated introduction 2012 data

28 Effects of climate change Predictions Uncertainty in the weather Drought Melting glaciers (sea level rise) Increase in violent weather (tornados, hurricanes) Changes in ecosystems crops invasive species species loss disease/health West Nile virus

29 For Next time: Time & Origins