Lecture 24 Flashcards
what did the world scientists warning to humanity say
in 1992, said carbon emissions and fossil fuels = the main issue and it beginning to get bad
in 2017 - the issues haven’t gone better or some are just getting worse
- new environmental issues = microplastics
-climate change is not a new issue we knew about this since 1985
explain the process of how heat gets trapped in the environment
the sun emits short strong wavelengths of sunlight
it gets absorbed by the surface of the earth
the warm surface then emits infrared radiation
the infrared radiation is absorbed by the atmosphere’s ozone layer and traps heat as the tradition is converted to water and CO2 which keeps the Earth warm
- the more human activity like cars, the more CO2, the more GHG and more global warming
how has climate change affected the Hadley cells
circulation patterns such as the Hadley cells are increasing in size
- since the earth is getting hotter, the Hadley cells shift poleward beyond their 30-degree latitude mark and cause shifts in the deserts
what happens to organisms as the climate changes
- they can acclimate to new conditions - phenotypic plasticity - they can change tolerance to new conditions in a life time
- they can adapt to new conditions
- they can migrate to more suitable conditions - range shift
- the can go globally or locally extinct = extirpation
what is acclimation
organism adjusts to changes in the environment in response to early/gradual exposure to environmental stress - this can reduce the negative impacts of the stress
- those who are suited to colder temperatures have more room to acclimate as the stress of CC is ongoing (crabs)
- those who are suited to warm temperatures increase their tolerance minimally
explain the relationship between hares, climate change and high predation-related mortality
hares in the winter = white
hares in the summer = brown
since climate change, snow is occurring later on in the year, but hares are not picking up on the change of season quick enough and are changing colour when it hasn’t snowed making them more visible to the predators
- climate change is also quickly melting the snow making the white colour cycle shorter
- it is seen that there is not enough plasticity to avoid the mismatches bc hares change colour regardless of the temperature - this mismatch only increases in the future as heat increases
- this slows the hare pop-down
- high selection for hares that change colours later on in the season
- more CC = decreased values of lambda which means less than 1
T/F hares will go extinct bc of their mismatch in colour season and the effects of climate change
false
- it is not for sure but it is an open ended question that depends on the amount and type of genetic variation in the coat colour changing gene
how does migration (range shifts) play a role in how species can counteract climate change
species are moving polewards where it is colder
- they are also moving up mountains but what If they run out of area or mountains? what is there is no other possible environment for them to live in on earth?
explain how pikas use range shifts to adapt to CC
pikas are adapted to cold mountain tops and its a death zone at the bottom of the mountains = too hot, now even more with climate change
- it is known that lots of pikas currently and in the past have died in high temperatures in the summer (above 26 degrees are not favourable)
- the pikas in the US may be endangered
- the pikas living in the rocky mountains = good
how is the migration for species limited
- if they cannot physically get across to migrate by physical boundaries
- pronghorn species gets caught in the fences and can not migrate, it is very good at running but can’t jump - this is a barrier that does not allow range shifting
T/F humans are creating the 6th extinction
true
what is Edward O Wilson say about extinctions
the loss of biodiversity is the more important process bc it is completely irreversible and least predictable - this is bc the earth biome is very unknown till this day
Approx how many species will go extinct from climate change
with a 1 degree increase, 2.8% extinct
with 4 degree increase, 16% extinct
- but these values only focus on the temperature factor, they do not include species interaction, dispersal differences, evolution
- this can increase or decrease the percentages
what is the best solution to reduce climate change
reduce CO2 emissions
