Impacts of CCSection 2 – reading is at the bookstore

But firstClimate Change conference began yesterday

Check it out

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Your paper

And second

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Field work on cc and gender … interested?

And Third

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Consequences of climate change

“In nature, there are neither rewards nor punishments – there are consequences.” –

Robert Ingersoll, 1833-1899

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Geological consequences Is it possible to unravel the climatic factors

from other causes of geological change?

Climatic events – waxing and waning of ice sheets, desiccation of continental interiors, drying up of oceans – had major impacts on the geology of the large parts of the Earth

Question: were they ‘cause’ or ‘effect’?

If ‘effect’ of plate tectonics and volcanism…

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2 issuesDo shifts in the climate exert a significant feedback on tectonic

activity (eg volcanism) by – say – changing the load on the Earth’s crust due to the build-up and collapse of polar ice sheets or changing sea levels?

If the climate can exert influence on tectonic activity, is it affected by extraterresrial effects (such as?)?

- No agreement currently on whether climate change exerts a significant effect on tectonic activity

- But – significant evidence to suggest there are various ways in which climate might create/help relieve stresses in the Earth’s crust

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Stresses in the Earth’s crust…

Example: during the last ice age, the eruption of volcanoes in the Med occurred more often at times of rapid sea-level change

Proposition: changes in the loading of the Earth’s crust by the build-up and collapse of ice sheets over northern Europe did influence the level of volcanic activity in the region

Unclear: how this feeds back into climate change

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Variations in the dayMore subtle global effect: variations in the length of the

day

If atmosphere circulates more rapidly, principle of the conservation of angular momentum requires that the Earth should slow down – an ever so tiny amount – to compensate for this atmospheric acceleration

due to a major ENSO warming event – equatorial winds speed up and Earth slows down

During sudden changes of the climate Earth could speed up or slow down by significant amounts could set up stresses and strains in the crust lead to increased volcanic activity more climate changes

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Climate change -> volcanoes?Was a big question during the Iceland volcano –

April 2010 “Iceland's Eyjafjallajokull has everyone discussing

what causes volcanic eruptions. One controversial hypothesis suggests climate change may play a role” http://theweek.com/article/index/202085/does-global-warming-cause-volcanoes-to-erupt)

Melting ice could provoke large eruptions…If Iceland's ice caps thaw, their weight diminishes, "freeing magma from deep below ground." Heavily ice-capped volcanoes like those in the Aleutian islands of Alaska or Patagonia in South America could be most at risk.

But Volcanic activity is caused by "magma rising to the surface, not glaciers melting”

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Extreme weather events“One swallow a spring does not make, and so a

single extreme weather event does not necessarily signify climate change. But how many swallows do?”

Recent years: increasing frequency of strong hurricanes; total # same

Recent years: record-breaking warmth

Recent years: local and regional unusual intense rainfall and drought

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A warmer world more thermal energy within the atmosphere and ocean-circulation system some of that energy greater evaporation (more rainfall) and wind speeds and storm size

Therefore: as the world warms, so the frequency of extreme weather events is likely to increase

What of the intensity and frequency of heat waves? (strong psychological factor) Also likely to increase. Heat waves over parts of US and Europe coincided with a specific atmospheric circulation pattern that is intensified by ongoing increases in greenhouse gases

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Hotter?Expect more extreme weather events

But not all extreme weather events are attributable to CC

Need to know: what is expected with natural variability assuming no carbon dioxide forcing and with climate forcing from additional anthropogenic greenhouse gases

UK HadCM3 model: an exceptionally warm summer up to 2020 will become a normal summer by the 2040s in Europe … they projected an increase 100-fold over the next four decades

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Wild species / flora and faunaGiven that:

Climate is a primary driven of biotic system Climate plays a central role in determining which

types of species inhabit which parts of the world The rate of warming is expected to continue to

increase – increasing by a minimum of 1.1 to potentially 6.4 degrees C or more

Expectation is…

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What we knowPlants and animals survived the less-rapid warming of the

post-Ice Age transition by shifting their ranges poleward and up in elevation, similar to the range shifts we have witnessed recently Many species have begun to move – moving poleward; blooming

earlier

What we have now Rapid temperature change In addition to everything else (such as?) “the combined effects of rapid temperature increases and other

anthropogenic changes collectively affect the flora and fauna of our planet more strongly – synergistically – than if each of these disturbances occurred alone.”

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Flora…Thermal growing season (TGS) could be extended due to

current warming Why? More days in the year in which plants can grow Primary biological productivity increases More carbon dioxide sequestered More water consumption (in addition to more water

consumption due to climate warming itself) Water demand depends on water supply – may have more

rainfall, or less, depending on region and locale

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Flora…Consider a species that is on the border of its

environmental range One environmental factor may increase (temp) – does not

mean that other environmental factors will increase (rain) to accommodate a species’ healthy growth

Even if more precipitation – still – expect more evaporation

In some places and for some species whose environment has changed, water availability could be a problem

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Alaskan White Spruce (Picea glauca)Thermal growing season (TGS) extended due to current

warming – yes

But – growth not increased Why: temperature-induced drought stress Interior of Alaska is semi-aird and in many places the

potential ET = annual P Increase potential ET through TGS and…

P. glauca is one of the most productive and widespread forest tree species in the boreal forest; plays important roe in northern-hemisphere terrestrial sink!

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Tropical-rainforest

A two decade long study (2004): of 18 tropical rainforest plots that were otherwise disturbed [study online] All trees over 10 cm in DBH were tagged Nearly 13,700 recorded Analysis done on genus level (due to high diversity) 244 genera – 115 used for statistical analysis

Within the plots, the rates of tree mortality, recruitment and growth have all increased No increase in pioneer species Increasing number of faster-growing trees Decline in slower-growing trees

What is causing these changes?

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What is causing these changes?

Previous disturbance unlikely Due to regional climate cycles – El-Nino related droughts which have

increased over the last century? [two other analyses say no] Rainfall changes (not drought) – i.e. decline in rainfall, river flow and

ground water – also discounted and rejected Accelerated forest productivity – due to increased carbon dioxide – or

due to increased cloudiness and higher airborne nutrient transfer from increased forest fires (both climate-related factors) Greenhouse gases the spur

These changes: local and global implications Carbon sinks? – increases in carbon storage by tropical trees may be

slowed by the tendency of canopy and emergent trees to produce wood of lower density as their size and growth rate increases

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Biological Dimension of Climatic-Change FingerprintWhat is a fingerprint

Fingerprints are changes that show a certain pattern that is unique to a specific climate-change driver.

[see online info from Pew Center on Global Climate Change]

Question: Are there any general effects of current warming

across natural systems? Is it possible to discern a global-warming

fingerprint?

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A biologist (Parmesan) and an economist (Yohe) studied this issue

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"A Globally Coherent Fingerprint of Climate Change Impacts across Natural Systems"

Friday, January 31, 2003

GARY W. YOHE CAMILLE PARMESAN WESLEYAN UNIVERSITY UNIVERSITY OF TEXAS - AUSTIN