climate change Flashcards
includes Tuvalu
what is ocean acidification
reduction of the pH of the ocean over an extended period of time prior to the industrial revolution that was 8.2 and is now 8.1 with it projected to reach 7.8 by 2100
how does ocean acidification decrease fish stocks
As carbon dioxide is dissolved into the ocean water the chemical reactions cause there to be fewer carbonate ions that can be available for shell or coral building. Corals are used as nurseries for fish so less coral = less fish and more smaller fish
How does ocean acidification impact people?
Smaller fewer fish 1 billion people rely on fish as main source of protein
How does rising ocean temperatures affect coral ecosystems?
Coral bleaching is when the coral gets stressed and expel the algae zooxanthella that live within them making the coral turn white record breaking temperatures at 20.96degrees centigrade in august 2023
List 5 facts about the Great Barrier Ree
Area: 348,700 km², 2600 km in length.
The Great Barrier Reef has around 3000 coral reefs and over 900 islands
More than 1,500 fish species live on the reef. (10% of the total world fish species). 6 species of turtle return to the reef to breed. 30 species of dolphin and whale have been recorded there.
Warmer ocean temperatures put stress on coral and lead to coral bleaching. Sediment, nutrient and agriculture pesticide pollution from river catchment run-off is also affecting the health of the Great Barrier Reef. The Great Barrier Reef has experienced several mass coral bleaching events in 1998, 2002, 2006, 2016, 2017, 2020. 2022 and 2024. Bleaching is expected to become an annual occurrence, when aerial surveys showed that over 50% of reefs experienced some coral bleaching.
How does loss of coral ecosystems threaten local communities?
Corals act as a natural coastal defence so if the coral are destroyed then mass flooding can happen
What are the causes of sea level change due to climate change?
Rising atmospheric temperatures mean oceans absorb more heat Oceans absorb about 90 percent of the Earths excess heat
How does thermal expansion of water causes sea level change?
Rising sea temperatures cause the water molecules to expand and so take up more space and the sea level rises.(thermal expansion )
How does the transfer of water from the land (melting of ice caps/glaciers) to the oceans cause sea level rise?
Antartica loses 105 billion tons of ice per year greenland loses 270 billion tons of ice per year glaciers have lost a volume of ice equivalent to nearly 26 meters of liquid water. Ice melting is the biggest cause of sea level rise in recent decades (21 percent)
Tuvula background
capital funafuti
9 islands
11000
4143 gdp USD
Pacific Ocean
80 percent of food is imported
how is sea level rise a threat to TUVALU
sea level rising by 5 mm per year since 1993 global average = 2.8 - 3.6 lots or erosion on west coast causing coral to be destroyed. Salt water contaminating fresh drinking water
Tuvalu - What are the impacts on communities?
loss of culture as more people move to NZ (250- a year) . Traditional food like Pulaka can not grow
Tuvalu - What are the short term adaptations to combat the impacts
adding water storage tanks
planting the more salt tolerant yucca instead of pulaka
importing rice
creating “food cubes” raised planting beds
Tuvalu - What are the long term adaptations to combat the impacts of sea level rise?
Migration to NZ and since 2023 - 120 Tuvaluans migrating to Australia per year. educating children at 6 about climate change
what do the Tuvalu red cross society do
work with locals plant new crops satellite phones added across islands running disaster and simulation drills planting new vegetation to act as natural buffer zone
How has global warming impacted on the extent of sea ice?
Decreasing by almost 13% per decade since 1979
The minimum is in September after summer melting. In 2022 the minimum was 4.9 million km2.
In 2012 it was 3.2million km2.
Sea ice thickness decreased on average from 4m to 1.25m since 1979, although altimetry has only been available since 2010.
Sea ice in the Arctic region has declined in recent decades in area and volume due to climate change. It has been melting more in summer than it refreezes in winter. Global warming, caused by greenhouse gas forcing is responsible for the decline in Arctic sea ice. The decline of sea ice in the Arctic has been accelerating during the early twenty‐first century, with a decline rate of 4.7% per decade (it has declined over 50% since the first satellite records)
What is the feedback between the extent of ice cover and the degree of warming?
In the arctic, positive feedback happens as whe nthe temperatures rise the thickness of the ice decreases Thereby allowing greater amounts of solar radiation to be absorbed by the ocean. The warming ocean then causes more ice to melt.
Describe the concept that there is a threshold beyond which change becomes irreversible
The IPCC sixth assessment Report(2021) suggested that Artic sea ice area will likely drop below 1 million Km ^2 in at least some Septembers before 2050. However the IPCC AR5 concluded that there is little evidence to suggest what the tipping point is but with rising temperatures there is an increase risk of going past the tipping point.
Arctic - What are the geo-political implications of changes in ice-cover?
There are 8 states that control the Arctic that is Canada Denmark Finland Iceland Norway Russia and Sweden. Russia Canada and Denmark have recently conducted geographical surveying of the ocean floor in an attempt to lay their claims on the resources as according to UNCLOS rules. Increased tension between Norway and Russia in Barents Sea, United states and Canada in the Beaufort sea and Russia and united states in the Bering sea The Artic holds 30 % of undiscovered gas and 13 % of undiscovered oil. Conflicts are aimed to be managed by the artic council.
Arctic - what are the impacts on indigenous peoples?
90 % of Inuit food is caribou fish or seal. 80 % of Inuit’s still hunt fish an d caribou. In winter Inuit men take their fishing equipment onto ice for 3 months to fish and hunt with the ice becoming thinner it is more dangerous to do. Due to Northern Sea route opening up for up to 6 -august to October - weeks tourist ships visit there 30% of Inuit’s make money by creating sculptures. Indigenous people have a relatively low adaptive capability due to low level of development and occasionally culture. Moving costs money and young people move away from the Artic as well as more food has to be imported. 70% of inuits are employed or get their money from hunting .Coasts are more affected by storms(as no sea ice) Intuits move inland
Arctic - What are the opportunities posed by the melting of sea ice
Enhanced marine fisheries for cod due to warmer water. Enhanced agriculture and forestry. Vegetation would shift northwards
Arctic - What are the threats posed by the sea ice melting
Increased conflict , reindeers change migration patterns, Decreased freshwater fisheries e.g. Artic Char threatened. Oil tankers have traversed Artic for 40 years so there is an increase in oil spills. Northwest Passage could be used as a alternative to Panama cannel intensifies USA Canada tens.
40% of permafrost will thaw in Siberia releasing large amounts of the greenhouse gas. Flows of meltwater will impact Arctic char. Artic water becomes less saline and warmer leading to a weaker gulf stream. Causing dramatic cooling over NW Europe. Infrastructure threatened
Arctic - How is the Arctic Council involved in the management of the Arctic region?
March 2016 Artic council gathered to address ongoing effects to decrease climate change in accordance with COP 21 . Largest coordinator and pillar of coordination among the artic states. Include indigenous groups
Arctic - How is the Arctic managed through the UN?
UNCLOS - set EEZS
IWC - international whaling comitee set quotas on the number of whales that can be caught 2 bowhead whales between 2019 and 2025 for green landers
ISA - international sea bed authority
