2.2 Consequences of climate change Flashcards
Predicted impacts on the physical environment can be modelled in a structured way by examining in turn possible consequences for which three spheres?
-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 effect of climate change on the hydrosphere?
Major ice sheets have lost mass, land-based glaciers have shrunk and Arctic sea ice cover has fallen significantly since 1979.
What is the effect of climate change on the atmosphere?
-The atmosphere (and the size of its carbon store).
-According to the IPCC, by 2100, global temperature is ‘likely’ to have risen by more than 1.5°C relative to 1850 and may rise by more than 4°C.
-The IPCC is ‘virtually certain’ of further permafrost melting, which will release further methane into the atmosphere.
What is the effect of climate change on the biosphere?
-In 2016, sea temperatures in the northern section of the Australia’s Great Barrier Reef rose 2–3°C above the normal peak of about 30°C, due to the strong El Niño weather system and a continuing trend towards global warming.
-Two-thirds of corals in one part of the reef have died as a result of coral bleaching in overly warmer water.
Describe the interaction between the hydrosphere, atmosphere, and biosphere
-These interactions are complex and hard to predict.
-At the global level, the atmosphere, hydrosphere and biosphere can be considered to be an open system that forms part of a chain.
-Interlocking relationships among these three subsystems (such as the ocean’s ability to absorb carbon dioxide) are what make climate change complex and difficult to model.
Why is it that if all human GHG emissions (new carbon flows) were to be halted tomorrow, some degree of change would remain inevitable?
-Because up to 40 per cent of the anthropogenic carbon stock already in the atmosphere will remain there for more than 1,000 years.
-It is therefore ‘virtually certain’ that some level of warming will continue well beyond 2100.
Approximately ___ of all water on Earth is oceanic and saline.
97%
Other than the 97% of water that is oceanic and saline, where is most of the fresh water that makes up the remaining 3% located?
-It is locked up in land ice, glaciers and permafrost.
-This makes up the majority of the Earth’s cryosphere.
-Aside from cryospheric water, a relatively tiny amount of fresh water is stored in the form of groundwater, lakes, soil, wetlands, rivers, biomass and the atmosphere.
What are the five locations of water in the cryosphere?
-Sea ice (e.g. the Ross Ice Shelf)
-Ice caps (e.g. the Iceland ice cap)
-Ice sheets (e.g. the Greenland ice sheet)
-Alpine glaciers (e.g. Mer de Glace, France)
-Permafrost (e.g. the Alaska North Slope)
What does evidence suggest about the changes taking place in the cryosphere?
-That in general, becoming reduced in size.
-Patterns and trends are not uniform, however.
-In Antarctica, at altitudes above 400 meters, glaciers are not thinning and may even be gaining mass.
-This is because snowfall is increasing across the Antarctic Peninsula (because warmer air can hold more moisture).
-However, this increased snowfall in upper regions is not enough to offset melting at lower attitudes. Overall, across the whole Antarctic Peninsula, around four-fifths of all glaciers are receding.
What are the human implications of the loss of some or all ice stores?
-Rising sea-levels
-Threatened loss of water supplies in some heavily-populated regions of the world
What is the cryosphere?
Portions of Earth’s surface where water is in solid form.
Define mass balance
The difference between the amount of snowfall gained by a glacier or ice sheet, and the amount of ice lost through the processes of calving (blocks breaking off) and/or melting.
What are the changing characteristics of ice caps as cryosphere storage?
-Ice caps occur all over the world, from the polar regions to mountainous areas such as the Himalayas, the Rockies, the Andes, and the Southern Alps of New Zealand.
-The Furtwangler Glacier on Kilimanjaro is Africa’s only remaining ice cap. It is melting rapidly and may soon disappear.
What are the changing characteristics of alpine glaciers as cryosphere storage?
-Alpine glaciers are thick masses of ice found in deep valleys or in upland hollows.
-These glaciers are particularly important in the Himalayas where meltwater from 15,000 Himalayan glaciers supports perennial rivers such as the Indus, Ganges, and Brahmaputra.
-In turn, these are relied on by hundreds of millions of people in South Asian countries (Pakistan, Nepal, Bhutan, India, and Bangladesh).
-Glacial retreat is clearly evident in aerial photographs of retreating glacier snouts and vanishing ice, for instance at Wolverine Glacier in Alaska or Argentina’s Upsala Glacier. China’s Urumqi No. 1 glacier has reportedly lost more than 20 percent of its volume since 1962.
What are the changing characteristics of permafrost as cryosphere storage?
-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 large amounts of carbon dioxide and methane, potentially affecting the global climate further.
What are the changing characteristics of Greenland and Antarctic ice sheets as cryosphere storage?
-An ice sheet is a mass of glacial land ice extending more than 50,000 square kilometers.
-The two major ice sheets on Earth today cover most of Greenland and Antarctica.
-Together, they contain more than 99 percent of the freshwater ice on Earth (the Antarctic ice sheet covers the same area as the USA and Mexico combined; the Greenland ice sheet is much smaller).
-Overall, Antarctica is losing more ice than it gains each year.
-The deficit is around 70 gigatonnes per year (1 gigatonne is 1 billion tonnes).
-Warmer surface air temperatures around the northern Antarctic Peninsula are having a dramatic effect.
What do scientists estimate would happen if the Antarctic ice sheet melted?
-Sea levels would rise about 60 meters.
What are ice shelves and where do they mostly exist?
They are floating platforms of ice that form where ice sheets and glaciers move out into the oceans; they exist mostly in Antarctica and Greenland, as well as in the Arctic near Canada and Alaska.
What are the changing characteristics of Greenland and Antarctic ice shelves as cryosphere storage?
The Antarctic ice sheet is melting from below, as increased upwelling of relatively warm, deep water comes into contact with the underside of the ice shelves.
What are the changing characteristics of Arctic sea ice as cryosphere storage?
-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.
-Future temperature rises are projected to be greatest at high latitudes and in recent decades the Arctic has heated twice as fast as the rest of the world.
-Some experts predict the region will be entirely ice free by 2050.
-Temperatures 20 °C higher than usual in late 2016 suggest it may occur even sooner.
Describe the movement of carbon from one store to another
-Carbon moves naturally from one store (such as vegetation biomass) to another (the atmosphere) in a continuous cycle.
-The processes by which the carbon moves between these stores are known as transfers or fluxes.
-The recent increase in GMST has begun to affect the pattern of global carbon stores and fluxes.
Give some facts to show the importance of the ocean in the carbon cycle
-The oceans contain around 40,000 gigatonnes of carbon in the form of dissolved carbon dioxide, marine organisms and dissolved organic matter.
-It is estimated that about 30 per cent of the CO2 that has been released into the atmosphere has diffused into the ocean through direct chemical exchange. Dissolving carbon dioxide in the ocean creates carbonic acid.
-If this had not occurred then atmospheric concentrations of carbon dioxide would be even higher than they are.
What has been the effect of the increased acidity of the oceans?
It has harmful effects for coral reef organisms and other sensitive species.
How is the pattern of carbon that is stored in ice changing?
Permafrost ice melting releases methane gas (CH4), which is one part carbon and four parts hydrogen.
How is the pattern of carbon stored in ecosystems changing?
-The total amount of carbon stored in the terrestrial (land) biosphere has been estimated at just over 3,000 gigatonnes of carbon.
-The largest amount is held in tropical and temperate forests. In some places, canopies of tall broad-leaved trees – and their associated under-canopies and shrub layers – have a growing risk exposure to wild fires and so-called ‘megafires’ that are reportedly increasing in frequency.
-There will most likely be a 35 per cent increase in the days with high danger of fire across the world by 2050.
In which areas of the world is vegetation at the greatest risk due to climate change?
In the Eastern states of the USA, southeastern Australia, the Mediterranean and southern Africa is at greatest risk.
How have sea levels changed naturally in the past?
-Historically, sea levels have always been higher during warm periods and lower during cold phases.
-During the most recent Pleistocene Ice Age, the UK and France were joined together following a eustatic fall in sea level of around 100 metres (the English Channel was drained entirely of water).
Define eustatic
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
What are the two reasons why a warmer climate results in deeper oceans?
-Melting of land-based glaciers and ice caps (and so increased runoff of water from the land to the sea)
-Thermal expansion of the oceans (water actually expands slightly in volume as its temperature rises, like liquid in a thermometer: in a warmer world the sea level would rise even if no ice had melted).
What are the different eustatic sea level rises that thermal expansion of the oceans and worldwide glacial melting are projected to bring?
-These combined processes are already giving rise to a total global average sea-level rise of approximately 3 millimetres per year.
-The IPCC projects a world sea-level rise of 260–820 millimetres by 2100, mostly due to thermal expansion.
-Significant glacier and permafrost meltwater runoff will produce another metre of sea-level rise by around 2200 (even if GHG emissions are cut significantly).
What will happen if no action is taken to cut GHG emissions?
Large-scale melting of the Greenland and Antarctica ice sheets could contribute 7-metre and 60-metre rises respectively (but this would take hundreds of years).
Diagram of a feedback loop showing why ice melting and sea-level rise might accelerate
What areas will suffer the worst consequences as a result of rising sea levels?
-Places that are coastal and low-lying, such as the Maldives islands.
-Other vulnerable places include estuaries or islands exposed to storm surges driven by cyclones, such as the Thames estuary and the Philippines.
-The places affected worst may be those suffering additionally from local sinking of the land.
-In these regions, the net effect will be an even greater rise in the level of water.
Give an example of a place that is being affected by rising sea levels
-The Ganges delta, in Bangladesh, is sinking by 10 millimetres a year as sediments settle.
-Some of the world’s poorest and most vulnerable people live here.
Why are the Marshall Islands threatened by rising sea levels?
Most of the Marshall Islands’ inhabitants live on islands barely 1 meter above sea level.
What is an 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.
-It is the occurrence of a value of a weather or climate variable (such as precipitation, wind strength or temperature) that is above or below a threshold value near to the previously observed maximum or minimum value.
Give some examples of scientific findings that show that while it cannot be said that a particular event was or was not caused by climate change, the scientists argue that they can explain how the odds of such events have changed in response to global warming (reword?)
-The devastating Texan heatwave that occurred in 2011 is now about 20 times more likely during La Niña years than it was in the 1960s.
-The UK’s exceptionally warm November 2011 temperatures are now about 60 times more likely to occur than they were in the 1960s.
Why do extreme weather events need looking at on a case-by-case basis?
-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 various extreme weather events and climate change is still debated.
-However, there are highly logical reasons why we should expect some hydro-meteorological hazards to become more commonplace on account of a rising GMST.
Why do extreme weather events need looking at on a case-by-case basis?
-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 various extreme weather events and climate change is still debated.
-However, there are highly logical reasons why we should expect some hydro-meteorological hazards to become more commonplace on account of a rising GMST.
Give examples of different hydro-meteorological hazards associated with extreme weather events
-Floods
-Cyclones/hurricanes/typhoons
-Droughts
-Landslides
When do floods occur?
-Floods occur when:
•Bankfull discharge is reached in a river
• High tides drive seawater inland
•Water collects locally in depressions due to high-intensity rainfall.
Where do floods occur?
-The global pattern of flooding is complex but includes high occurrence:
•Along coastlines and on the floodplains of major continental rivers
•In areas with a monsoon climate, especially deforested regions.
Why might climate change the strength or frequency of floods?
-In a warmer world, more evaporation takes place over the oceans – and what goes up must ultimately come down.
-Climate scientists believe rainfall patterns are changing in many parts of the world as the world’s oceans warm.
What are the characteristics of cyclones/hurricanes/typhoons?
-Most tropical cyclone (hurricane and typhoon) tracks lie 5–20° north or south of the equator.
-These tropical storms start life as a body of warm, moist air over a tropical ocean that has reached the critical temperature of 26°C.
-Driven by the rotating Earth’s Coriolis force, a flow of air develops around a central eye.
-Mid-latitude depressions form between 40°N and 60°N (where tropical and polar air masses converge at the polar front, under conditions of divergent flow in the jet stream).
-‘Bomb’ depressions are exceptionally severe.
What are cyclones?
Cyclones, or storms, are low-pressure weather systems that bring multiple risks of high wind speeds, heavy rainfall, and flooding.
Why might climate change the strength or frequency of cyclones?
-The devastation of New Orleans by Hurricane Katrina in 2005 ignited the important debate about whether climate change may be leading to the development of more high-intensity storms.
-Cyclones draw strength from heat in ocean surface waters; basic physics and modelling studies suggest that tropical storms will become more intense, because warmer oceans provide more energy that can be converted into cyclone wind.
What are droughts?
A drought is an extended period of low rainfall relative to the expected average for a region.
In what regions do droughts occur?
-In semi-arid or Mediterranean climates, when the rainy season is late
-In the mid-latitudes, due to changes in the behavior of air masses and the jet stream (parts of Europe had severe droughts in 1976, 2006, and 2011)
-Either side of the Pacific Ocean due to ENSO cycles
Why might climate change the strength or frequency of droughts?
-Europe’s heatwave of 2003 led to 35,000 deaths, many of them elderly.
-This sparked debate on whether events that might previously have occurred once every 200 years might begin to recur every 20 or 30 years.
-Many parts of the world are projected to experience temperature rises that may lead to increasing frequency and severity of drought
Where do landslides occur?
-Landslides occur on slopes whenever the shearing stress acting on the slope exceeds its shearing resistance.
-For instance:
•Along coastlines during storms
•On slopes that are saturated by heavy rain.
Why might climate change the strength or frequency of landslides?
More landslides are to be expected in some coastal areas if a combination of higher tides and stormier conditions results in increased rates of coastal erosion.
How are biomes affected by climate change and why?
-Expected ecological changes linked with climate change include the longitudinal shift of vegetation biomes.
-This is because the characteristics of the vegetation are determined by the climate currently found in different places.
What is the tree line and how is it shifting?
-The boundary between coniferous forest and the polar tundra ecosystem in high latitudes of the northern hemisphere is called the tree line.
-The tree line is definitely moving north on average.
-In places, the movement may equate to around 100 metres per year.
-The rate of movement is uneven, however, on account of local factors, including suitable soil and the absence or presence of animals that destroy saplings.
How is the tundra biome changing due to climate change?
The tundra biome is predicted to shrink in size by at least 20 per cent this century on account of the northward movement of trees and the thawing of permafrost.
What is a biome?
-Large planetary-scale plant and animal communities covering vast areas of the Earth’s continents.
-For example, tropical rainforest, desert and grassland.
What is a tundra?
-A ‘cold desert’ ecosystem composed of tough short grasses that survive in extremely cold, sometimes waterlogged, conditions at high latitudes where trees cannot grow.
-The tundra is underlain by permafrost.
Define the tree line
The boundary between the coniferous forest and tundra biomes.
Where are major changes to food webs likely to occur due to climate change and why?
In polar regions due to the larger temperature rises expected there.
How are species on land going to be affected by climate change?
On land, many species will need to migrate northwards permanently, mirroring expected shifts in biome distribution patterns.
How will annual animal migration patterns be affected by climate change?
-They will also be modified.
-Canada Geese will not need to fly as far south during winter; currently, around 90,000 of these birds spend the winter in UK estuaries and saltmarshes.
-In the future, they may not need to travel as far south from their Artic breeding grounds.
How does climate change affect polar bears?
-Much of the polar bear’s time is spent hunting for seals along the northern edges of the Arctic Ocean, in places where there is very little plant life.
-When seals are scarce, the polar bears roam inland into the tundra, in the very far north of Russia and Canada.
-In contrast, brown bears graze and hunt at the southern edges of the tundra, close to the forest boundary.
-To escape freezing conditions and food scarcity in winter, they hibernate, insulated by fat from the cold.
-In a rapidly warming scenario for the Arctic, many aspects of bear behaviour may change.
How does climate change affect forests in the Arctic?
-Global warming will increase forest fires and insect-caused tree death in Arctic regions.
-The loss of old-growth forest represents a potential habitat loss for lichens, mosses, fungi and birds such as woodpeckers.
How does climate change affect ocean life in the Arctic?
-Ocean life will be affected as Arctic ice thins and shrinks, and the water below warms.
-Summer ice has already decreased by about 10 per cent since 1979.
-There was a slight recovery in 2007–08 but the underlying trend is loss.
Define risk
A real or perceived threat against any aspect of social or economic life, or the environment.
What is the risk equation used for?
It is a way of exploring the concept of risk, which involves highlighting the role that a society’s vulnerability and capacity to cope (or resilience) play in determining the size of a threat.
What is the risk equation?
Risk can be a threat to ___
People’s lives and/or their economic prosperity.
What is a population’s capacity to cope, or level of resilience, determined by?
-Wealth (a rich country can afford adaptation costs e.g. flood defences)
-People’s level of preparedness (do floodplain residents keep a ‘flood kit’ for emergencies?)
-The emergency service response (national or international)
What is vulnerability and what groups of people are most vulnerable to hazards?
-Vulnerability is a function of where people live and their lifestyles. (Do they live by a river? Were they outside when the storm or flood struck?)
-Vulnerable people are high-risk groups (such as the elderly or deaf people, or migrants with poor language skills who may not understand hazard warnings).
How is climate change expected to impact extreme weather events?
It is expected to increase the strength, frequency or unpredictability of extreme weather events.
How is Europe going to be affected by climate change? (examples)
-Flood risk from heavy rain is one of the main threats to the UK. The estimated cost of damage from flooding could be 12 billion pounds by the 2080s.
-The UK may be affected by sea level rise in Europe, putting the UK’s coastal defences under increased strain.
-In the UK, average temperatures are likely to increase, as will the risk of diseases such as skin cancers and heat strokes. Milder winters might lead to a decline in winter-related diseases.
-Ski tourist resorts such as those in the Alps may closer or have shorter seasons as there may be less snow.
-The Mediterranean region may see increased drought.
How is Africa going to be affected by climate change? (examples)
-Drought is likely to put pressure on food and water supplies in sub-Saharan Africa due to higher temperatures and less rainfall.
-Health in southern and eastern Africa may decline as the frequency of malaria could increase in hot and humid regions that remain hotter for longer in the year.
How is South America going to be affected by climate change? (examples)
-In the Amazon rainforest, a modest level of climate change can cause high levels of extinction. Eastern Amazonia may become a savannah with warmer temperatures and less soil moisture.
-South America is expected to decrese in maize, soybean, and wheat crop yields.
How is North America going to be affected by climate change? (examples)
-The tree line of the Sub-Arctic boreal forests is expected to retreat north as temperatures rise.
-It is likely that argiculture may yield more wheat, soybean, and rice but see a decrease in maize yields in North America.
-Forests in North America may be affected more by pests, diseases, and forest fires.
How is Asia going to be affected by climate change? (examples)
-Around 70% of Asia may be at an increased risk of flooding.
-The fishing industry in East Asia is expected to decline due to higher temperatures and more acidic sea.
How is climate change going to affect agriculture?
-Climate may change in ways that threaten both subsistence agriculture (the informal agricultural economy) and cash crops produced by the world’s agribusinesses (large transnational farming and/or food production companies, such as Cargill or Del Monte).
-One third of the world’s population earns a living farming – and the other two-thirds depend on the food these farmers produce.
How will desertification (due to climate change) affect agriculture?
Desertification and the extension of arid conditions in sub-Saharan Africa could adversely affect agriculture in regions like Same District in Tanzania and Kitui District in Kenya.
How will soil erosion (due to climate change) affect agriculture?
-Soil erosion by water is a major threat to the sustainability of agriculture in many tropical and subtropical regions in both low-income and high-income countries.
-Global warming is expected to lead to a more vigorous hydrological cycle, including more total rainfall and more frequent high-intensity rainfall events.
-These rainfall changes could have significant impacts on soil erosion rates.
-Rainfall erosivity levels may be on the rise already across parts of the USA.
-When rainfall amounts increase, erosion and runoff will increase at an even greater rate: the ratio of annual rainfall increase to erosion increase is in the order of 1 : 7.
How will productive land be affected by climate change?
It could be lost to sea-level rise, especially valuable fertile alluvial soils on river floodplains and deltas.
How will hurricanes (due to climate change) affect agriculture?
-Increased hurricane frequency could devastate agriculture
-E.g. Hurricane Katrina cost the USA US$1 billion in crop and poultry losses
How might climate change have positive impacts on agriculture?
Shifting rainfall, temperature and biome patterns mean that certain areas will become more productive or better suited to higher-value crops or land uses.
Give an example of how climate change might have positive impacts on agriculture (Greenland)
-Positive impacts on the limits of cultivation can already be seen in southern Greenland where the growing season is a month longer than it used to be.
-In 2007, broccoli was grown there for the first time.
Give an example of how climate change might have positive impacts on agriculture (grapes)
-The climatic conditions needed for different varieties of grape to prosper are highly specific.
-As a result of climate change, some places are gaining newfound success as wine-growing regions.
-Vineyards in southern England have gone from strength to strength in recent years, for instance. English wine producers attribute their newfound success to warmer temperatures produced by climate change (helped also by geological similarities between southern England and France’s Champagne region).
What health hazards can climate change cause?
-Increase in vector-borne diseases
-Ebola outbreaks
-Food insecurity
Explain how climate change can cause an increase in vector-borne diseases
Vector-borne diseases such as malaria and water-borne diseases (diarrhoea) could increase with climate change.
Explain how climate change can affect ebola outbreaks
-Some scientists think that climate change may have played a role in ebola outbreaks by changing the behaviour of bats (the suspected carriers of the 2014 ebola outbreak).
-Computer modelling suggests that, in parts of central and western Africa, the range of some bat species could be expanding.
-This would mean increased contact between bats and humans.
Explain how climate change can cause food insecurity
Some places may experience increasing food insecurity alongside water shortages: less food will be produced in regions where rainfall decreases and desertification occurs (such as the Sahel and large parts of Asia, according to IPCC projections).
Define food insecurity
When people cannot grow or buy the food they need to meet basic needs.
Give some statistics to show how climate change is displacing people
UN agencies estimate that nearly 10 million people from Africa, south Asia and elsewhere have migrated or been displaced by environmental degradation, weather-related disasters and desertification in the last 20 years.
Who is displaced by severe climates?
The very poor who are unable to afford to travel long distances, they are likely to become IDPs or refugees in neighbouring states.
How are rising sea levels affecting human migration?
-More people may become climate change refugees on account of rising sea levels.
-Dozens of islands in the Indian Sunderban region are being regularly flooded, threatening thousands.
-The Maldives, located southwest of India and Sri Lanka, is gravely at risk from rising sea levels.
-It consists of a chain of 1,190 low-lying islands that are surrounded by the waters of Indian Ocean.
-Bangladesh is the most vulnerable large country, with 60 per cent of its land less than 5 meters above sea level.
-Bhola villagers will have no option but to migrate; many will go to the slums of Dhaka.
Give an overview of how climate change is affecting shipping movements in an ice-free Arctic
-With summer sea ice currently shrinking by 12–13 per cent a decade, the Arctic Ocean could be ice free by 2050.
-Already, it is becoming more accessible for shipping.
Give some examples of how shipping is becoming more accessible in the Arctic
-In 2017, new icebreaking liquid natural gas (LNG) carriers began to travel from Siberia to the Pacific. Russia is no longer wholly dependent on selling gas through pipelines to Europe.
-The route from Yamal, Siberia to Japan takes just 14 days during summer months via the new northern sea route along the Arctic coast of Russia.
-In winter, when sea ice reforms, the route closes. In the future, however, it may be possible for vessels to make the same journey all year round.
What human processes heighten climate change risks?
-Population growth
-Megacities
-Deforestation
-International conflicts
Explain how population growth heightens climate change risks
Population growth can lead to increased numbers of people living in a vulnerable state of poverty.
Give an example of how population growth heightens climate change risks
The number of people living in sub-Saharan Africa has doubled since 1980, meaning that twice as many people are now at risk of famine when rains fail.
Explain how megacities heighten climate change risks
-Many large cities and megacities are places where predicted climate change risks are high.
-In particular, many more people will live in increasingly high-risk urban zones situated along floodplains and coastlines.
Give an example of how megacities heighten climate change risks
-Between 2010 and 2020, Lagos and Kinshasa (Democratic Republic of Congo), will add 3.5 million and 4 million people to their respective populations.
-Both have a known flood risk and much of the new housing growth will be precisely in areas where the risks are greatest (for instance, in areas of informal slum housing built around the lagoons or on coastal sandbars in Lagos)
Explain how deforestation heightens climate change risks
-Deforestation throughout Southeast Asia (Bangladesh, Malaysia, India and Indonesia) has modified hydrological systems, making overland flow far more likely.
-The biomass interception store has been removed (which naturally functions like a valve, slowing down the passage of rainwater onto the land).
-Inevitably, flooding increases in deforested areas like the Ganges basin.
Explain how international conflicts heighten climate change risks
Deep-rooted conflicts, such as India and Pakistan’s dispute over the Kashmir region, could be exacerbated by food and water shortages in the future, potentially jeopardizing international cooperation aimed at tackling climate change.
