2.2 - Consequences Of Global Climate Chnage Flashcards
How can we examine the possible affects of climate change
We can examine the possible effects by looking at the consequences for…
○ The hydrosphere: the world’s water cycle and stores
○ The atmosphere: and the size of its carbon store
○ The biosphere: the world’s ecosystems, flora and fauna
What is the water and carbon storage
Approximately 97% of all water on Earth is oceanic and saline and most of the freshwater that makes up the remaining 3% is locked up in land ice, glaciers and permafrost. Aside from cryospheric water, a relatively tiny amount of freshwater is stored in the form of groundwater, lakes, soil, wetlands, rivers, biomass and the atmosphere.
What is the cryosphere
The portions of the Earth’s surface where water is in solid form. The available evidence shows that that the cryosphere is, in general, becoming reduced in size.
What are ice caps
Ice caps occur all over the world, from the polar regions to mountainous areas such as the Himalayas. The Furtwangler Glacier on Kilimanjaro is Africa’s only remaining ice cap and it is rapidly melting and may soon disappear.
What are glaciers
Glacial retreat is clearly evident in aerial photographs of retreating glacier snouts and vanishing ice. The Himalayan alpine glaciers are extremely important as meltwater from the 15’000 glaciers support perennial rivers such as the Indus, Ganges. In turn, these are relied on by hundreds of millions of people in South Asian countries.
What is permafrost
The vast permafrost ring around the Arctic Ocean has already begun to thaw in places where temperatures have risen by several degrees since the 1960s. This melting is releasing vast amounts of carbon dioxide and methane, potentially affecting the global climate further (positive feedback loops).
What are ice sheets
An ice sheet is a mass of glacial ice extending more than 50’000km2. The two major ice sheets on Earth today cover most of Greenland and Antarctica. Together they contain more than 99% of the freshwater ice on Earth. Overall Antarctica is losing more ice than it gains each year and scientists estimate that if the Greenland ice sheet melted altogether, then sea level would rise about 6m and if the Antarctic ice sheet melted, sea level would rise by 60m.
What are ice shelves
Floating platforms of ice that form where ice sheets and glaciers move out into the ocean; these exist mostly in Antarctica and Greenland. The Antarctic ice sheet is melting from below, as increased upwelling of relatively warm, deep water comes into contact with the underside of ice shelves.
What is the article sea ice
Within the Arctic Circle lie Northern parts of Russia, Canada, Alaska (USA), Greenland and Scandinavia, as well as the Arctic ocean, parts of which remain covered with sea ice all year. In recent decades, the Arctic has heated twice as fast as the rest of the world and some experts estimate that the region will be entirely ice free by 2050. → There is the potential for economic gain through this melting as countries could benefit from the oil extraction in the Arctic Ocean and the North-West shipping passage, which would drastically reduce shipping times between many regions of the world.
Where are the 5 places that cryospheric water is stored
- sea ice
- ice caps
- ice sheets
- alpine glaciers
- permafrost
How does carbon move
It moves naturally from one store to the other in a continues cycle
How much carbon does the water store
40,000 gigiatones
What is the issue about carbon dioxide being in the water
is estimated that about 30% of all the CO2 that has been released into the atmosphere
has diffused into the ocean through direct chemical exchange. Dissolving carbon dioxide
into the ocean creates carbonic acid. → has harmful effects for coral reef organisms.
What is ecstatic
A worldwide change in average sea level resulting from a warming or cooling climate affecting the volume and/or depth of water in the oceans.
How does a warmer climate result in deeper oceans
- melting of land based glaciers and ice caps
- thermal expansion of the ocean (water exapands slightly in volume as temp rises)
How will rising sea levels affect some countries
Rising sea levels will have a larger impact on some countries compared to others. The worst impacted will be places that are coastal and low-lying such as:
○ The Maldives: 311’000 people live on 1’196 islands, most just 2m above sea level.
○ Tuvalu: The 11’000 citizens of Tuvalu will have to abandon their homes by the end of the
century and have appealed for help in evacuating. 4’000 islanders have already relocated
to New Zealand.
What places will be affected the worst by rising sea levels
The places affected the worst may also be suffering from local sinking of the land (isostatic
change), in these regions the net effect will be an even greater rise of water:
○ The Ganges Delta: Sinking by 10mm a year as sediments settle. Some of the world’s
poorest and most vulnerable people live here.
○ Southern England: Sinking by several millimeters a year due to a geological process
known as isostatic tilting, triggered by the end of the last Ice Age.
What is extreme weather event
An occurrence such as drought or a storm which appears unusually severe or long-lasting and whose magnitude lies at the extreme range of what has been recorded in the past.
What is the state of climate report published in 2012 by the bulletin of the American meteorological society (AMS) show
The State of the Climate report published in 2012 by the Bulletin of the American Meteorological Society (AMS) showed a new emerging consensus among leading meteorologists. While they cannot say a particular event was or was not caused by climate change, the scientists explain that they can explain how the odds of such events have changed in response to global warming.
○ The devastating Texan heatwave that occured in 2011 is now about 20 times more likely during La Nina years, than it was in the 1960s. ○ The UKs exceptionally warm November 2011 temperatures are now about 60 times more likely to occur than they were in the 1960s.
- Natural variability will always bring periodic extreme floods, droughts and heatwaves to different places; it takes years of data to distinguish this from any underlying trend. For this reason, the precise link between climate change and extreme weather events is still debated.
What are 4 extreme weather risks
- floods
- cyclones
- drought
- landslides
What is a flood
Flooding usually has a high occurrence along coastlines, on the floodplains of major rivers and in areas with monsoon climate, especially deforested regions. Climate change can increase the risk of flooding through increased evaporation due to warmer oceans & temperatures, hence more precipitation and rising sea levels mean coastal areas are at greater risk of flooding.
What is a cyclones
Most tropical cyclone (hurricane/typhoon) tracks lie 5-20o north or south of the equator. These tropical storms start as a body of warm, moist air over a tropical ocean that has reached the critical temperature of 26oC. These can be amplified by climate change, as cyclones draw strength from the heat in ocean surface waters, hence with climate change, warmer oceans can provide more energy that can be converted into cyclone wind.
What is a drought
Drought is an extended period of low rainfall relative to the expected average for a region. In the IPCC climate change scenarios, many parts of the world are expected to experience temperature rises that may lead to increasing frequency and severity of drought.
- Europe’s heatwave of 2003 led to 35’000 deaths, many of them elderly. This sparked debate on whether events that previously occurred once every 200 years, may start occurring on a more regular basis such as every 20 to 30 years.
What is a landslide
Landslides occur on slopes whenever the shearing stress acting on the slope exceeds the shearing resistance e.g. along coastlines during storms, on slopes that are saturated by heavy rain. More landslides are expected in some coastal regions if a combination of higher tides and stormier conditions results in increased rates of coastal erosion.
