Climate Flashcards
Experts state that by this year, climate change will truly be irreversible unless our carbon emissions are reduced significantly. What year has been stated by scientists in the IPCC?
2030
what are human activities doing to Earth’s climate?
changing it by causing increasingly disruptive societal and ecological impacts
what are the impacts creating?
hardships and suffering
to limit the impacts, the world’s nations have agreed to hold the increase in global average
temperature to?
well below 2°C (3.6°F) above pre-industrial levels.
what should global society do to achieve the goal of keeping global avg temp low?
reduce its greenhouse gas emissions
According to the Intergovernmental Panel on Climate Change (IPCC), global carbon dioxide
(CO2) emissions must reach net zero by around…to have a good chance of limiting warming by about…?
2070;2050
what will the 2050 and 2070 targets require in terms of energy source?
a substantial near-term transition to carbon-neutral energy sources
what will the 2050 and 2070 targets require in terms of carbon efficiency?
adoption of a more carbon efficient food system and land use practices
what will the 2050 and 2070 targets require in terms of removal of CO2?
enhanced removal of CO2 from the atmosphere through a combination of ecological and technological approaches
what should society be prepared to do?
cope with and adapt with the adverse impacts of climate change
done “ “ “, the needed transformations provide a pathway toward?
strategically, efficiently, and equitably; greater prosperity and well being
what will inaction prove?
very costly for humans and other life on the planet
over the past century, as a result of burning fossil fuels and other human activities, atmospheric concentrations of greenhouse gases have risen to levels unprecedented in?
at least the last 800,000 years
what decade is the hottest in the history of modern civilization?
current decade
what is the dominant cause of the observed warming since the mid-20th century?
human activities, especially emissions of greenhouse gases
what other changes related to heating have been documented in terms of heat waves?
more frequent heat waves on land and ocean
what other changes related to heating have been documented in terms of ice?
reductions in:
Artic sea ice
Northern Hemisphere’s snow cover
Greenland and West Antarctic ice sheets
mountain glaciers
what other changes related to heating have been documented in terms of global water cycle?
intensifying precipitation events
what other changes related to heating have been documented in terms of sea levels?
rising sea levels
what are greater CO2 concentrations in the atmosphere affecting in terms of plants and the ocean?
the growth and nutritional value of land plants
directly acidifying ocean waters
The Paris Agreement
legally binding international treaty on climate change
by whom was The Paris Agreement adopted by?
196 Parties at COP 21 in Paris
COP 21
21st Conference of Parties (convention on climate change)
when was the Paris Agreement adopted?
12 December 2015
when was the Paris Agreement entered into force?
4 November 2016
what is the Paris Agreement’s goal?
to limit global warming to well below 2, preferably to 1.5 degrees C, compared to pre-industrial level
to achieve Paris Agreement’s goal, what have countries aimed to do regarding emissions?
reach the global peaking of greenhouse gas emissions as soon as possible to achieve a climate neutral world by mid-century
The Paris Agreement is a landmark in? why?
the multilateral climate change process because for the first time a binding agreement brings all nations into a common cause to undertake ambitious efforts to combat climate change and adapt to its effects
the implementation of the Paris Agreement requires what type of transformations?
economic and social transformations based on the best available science
what does the Paris Agreement work on?
a 5 yr cycle of increasingly ambitious climate action carried out by countries
When and who signed up to the Paris Agreement?
Dec 2015; 194 states and the European Union
The Paris Agreement is the most important pact for?
international cooperation to tackle climate change
by signing the Paris Agreement, what have the world’s nation have committed to do?
limit the increase in global warming to ‘well below 2°C’, with a goal to keep it to 1.5°C
what have the world’s nations set an aim to peak?
global emissions as soon as possible
what have the world’s nations set an aim to a balance? when?
achieve a balance between human emission produced and the removal of greenhouse gases from the atmosphere in the second half of the century
what is net-zero emissions?
human emissions produced = removal of greenhouse gases from atmosphere
what have developed countries also committed to provide?
more financial support for developing countries to act on climate change
what have countries have committed to by signing the Paris Agreement?
to submitting and delivering on their own voluntary pledges that set out how they will lower their emissions and adapt to climate change
NDCs
Nationally Determined Contributions
What are NDCs?
a country’s own voluntary pledges that set out how they will lower their emissions and adapt to climate change
what are the NDC pledges monitored by?
“global stocktake”
through an international mechanism that reviews collective progress on the goals of the Agreement
when will the global stocktake happen?
first in 2023
then subsequently every five years
countries are legally allowed to do what with their pledges under the Paris Agreement?
submit their pledges
how should delivering the pledges be ensured?
must be ensured and enforced through national laws and policies
what comes from publicizing the different national pledges transparently?
the Agreement makes it possible to hold states accountable if they fail to deliver on their promises
what does the global stock take mechanism put pressure on?
pressure on countries to increase their level of ambition over time by regularly reviewing process on the shares global goals
why do some international relations experts claim that the Paris Agreement was an important new step for global climate change action?
by relying on voluntary promises and transparent review processes, it sidesteps the thorny question of how to reach an international agreement on legally binding targets for lowering greenhouse gas emissions
what is hoped from the Paris Agreement?
hoped that this approach creates a more realistic path for international climate change action
what is climate
the statistical description (both mean and variability) of the atmosphere, ocean, land, cryosphere system over a few decades
what is climate characterized by? what does it depend on?
the balance of incoming and outgoing energy which strongly depends on the composition of the atmosphere
what can climate be affected by?
human induced changes in atmospheric composition (greenhouse gases and aerosols) and land surface use/cover
what is climate also influenced by naturally?
natural variability which includes decadal to multi-decadal fluctuations of ocean circulation and temperature in the Atlantic and Pacific basins
what is the most prevalent greenhouse?
other than water vapor, CO2
why is CO2 concentration rising?(3)
mainly from fossil fuel combustion, cement production, and deforestation
how much of the anthropogenic CO2 input into the atmosphere has remained in the atmoshpere?
half of it
what happened to the rest of the anthropogenic CO2 not in the atmosphere?
taken up by the oceans and terrestrial biosphere (soil and plants on land)
what are the two CO2 reservoirs?
oceans and terrestrial biosphere
how much and when does the atmosphere exchange CO2 with the 2 CO2 reservoirs?
routinely exchanges large amounts of CO2,
seasonally
once CO2 is introduced, how long can it stay in the atmosphere?
1000 years or more before it is removed by natural process
how long has more than 50% of the introduced CO2 remained in the atmopshere?
at least 50 years
how long has more than 30% of the introduced CO2 remained in the atmopshere?
at least 100 years
what is another important greenhouse gas?
water vapor
how is water vapor unlike CO2?
it responds quickly to temperature change
since water vapor responds quickly to temperature change, what does it do?
acts as a feedback, amplifying the response of the climate system to changes in radiative forcing, for instance long lived greenhouse gases like CO2
what is radiative forcing?
when the amount of energy that enters the Earth’s atmosphere is different from the amount of energy that leaves it
third important greenhouse gas
methane
how is methane produced?
naturally, primarily by emissions from wetlands and wildlife, and from human activities such as agriculture, landfills, and fossil fuel extraction processes, with the human activities responsible for the majority of emissions today
what is methane a by-product of?
the hydraulic fracturing (fracking) process for extracting oil and natural gases from underground
how is methane compared to CO2?
shorter-lived and much less abundant, but a much more effective greenhouse gas per molecule
what is the warming potential of methane compared to CO2?
more than 30 times the warming potential of C02 by weight when compared over a 100 yr period
what was the concentration of methane before the industrial revolution?
less than 800 parts per billion
what was the concentration of methane after the industrial revolution?
at over 1,800 parts per billion
as the climate changes, how will the production of natural methane change? why?
will likely increase due to thawing of previously frozen carbon-rich soils in the permafrost zones of the high-latitude continents and
the possible mobilization of methane trapped in hydrate form in oceanic sediment
what are atmospheric aerosols?
tiny (nano- to micrometer diameter) solid particles and liquid droplets suspended in the
atmosphere like dust and sulfates from air pollution
how can human activity affect atmospheric aerosols?
through changes in the number and physical properties of them
what do aerosols modify?
visible and infrared radiation
what do aerosols influence?
the spatial distribution of clouds and precipitation
what do aerosols originating from human activity do?
act to cool the planet, partly counteracting greenhouse warming
how long are aerosols suspended in the troposphere (lowest region of atmosphere)?
much shorter for greenhouse gases such as CO2
what are stratospheric aerosols generated by?
occasional large sulfur-rich volcanic eruptions
at can stratospheric aerosols do to the global surface temperature?
reduce it for a few years
changes in what influence the surface exchange of water and energy with the atmosphere? what does this generate?
changes in land surface use from agriculture, irrigation, deforestation, and urbanization; regional climate change
over the next…years Earth’s surface will warm at least as much as it did in the past…years, and perhaps.-.times more
100; 100; 2-6
what will happen to the proportion of global warming that is offset by cooling from human sources of aerosols?
may diminish in the future
what will happen to global warming and sea level during the next few decades if atmospheric greenhouse gas concentrations could be held constant at their present level? why?
continue to rise
inherent slowness with which the oceans and polar ice sheets respond
what do oceans and polar ice sheets respond to?(3)
surrounding temperature, the input of heat, and changes in the
chemistry of the air and oceans.
what do climate models project the global average sea level to be at the end of the twenty-first century relative to the 1850-1900 period?
0.3-1.2 m higher (1-4 ft 0
what do climate models project the global average surface temperature to be at the end of the twenty-first century relative to the 1850-1900 period?
warmer by more than 1.5 C and up to 4 C depending on future emission scenarios
if emissions are restricted to the level of current international agreements, what is the range for the global surface temperature increase?
2.6-3.1 C
how much more are oceans projected to be acidic by the end of this century?
an additional .3-.4 pH decrease or +150% acidic
at regional scales, what do climate model project regarding the subtropics?
a general reduction of precipitation
what does the reduction of precipitation with warmer temperatures do?
have the effect of intensifying drought
at regional scales, what do climate model project regarding high latidtudes?
increase of precipitation, associated with increasing extreme precipitation events
what is the sea ice in the Artic Ocean projected to become?
seasonal or disappear entirely from some places, making the continental margins of the Arctic more prone to damaging storms and ocean waves
how fast is the warming in Alaska? what will this do?
faster than other parts pf the US will continue, with likely further thawing of permafrost
what global-scale effects does the projected warming have on? (4)
sea level rise
precipitation
heat extremes
ecosystem health
ways to avoid projected heating? (3)
barring large increases in volcanic activity/decreases in solar energy output
reducing amount of greenhouse gas emitted by human activity
accelerating the removal of these gases from atmosphere
what will adaptation allow for?
ameliorate at least some of the impacts of projected climate change on economies and human health
how are climate projections into the future made?
using computer programs that model the atmosphere-ocean-land surface-cryosphere, based largely on fundamental physical laws and well understood physical principles
what do the programs simulate?
explicitly simulate the large scale motions of the atmosphere and ocean (approximately 100km (60miles) or larger)
how do the simulated climates work?
we subject them to time-dependent greenhouse gas concentrations and other forcings, with those concentrations allowed to evolve in the future based on emission hypotheses, and the simulation responds to such changed in atmospheric composition
another word for emission hypotheses
emission scenarios
what do climate projections from calculations of large scale motions focus on?
identifying the average state and extreme state of the atmosphere and ocean, summarized on the time scales of decades rather than an instantaneous future state of the entire system
what do climate projections depend on?
evolution of the energy budget and its influence on the climate system’s slowly varying components - ocean, land surface, and the cryosphere- and their interactions
what can natural variability obscure?
anthropogenic influences on climate at the multidecadal scale
ex. slower pace of atmospheric warming during the first decade of the
twenty-first century and a more rapid pace during the mid-2010s
what is one thing about warming that is seen in projections of future climate?
changes in the pace of warming
climate model strength
reliably represent many of the fundamental processes that govern weather and climate, including midlatitude storms, heat waves, droughts, and extreme seasonal precipitation.
so, many models are able to simulate the broad features of the twentieth-century climate
climate model weakness
some crucial processes like clouds and convection, ocean eddies, deep water formation, and carbon cycle remain crudely represented. These deficiencies are thought to underpin model errors in the
representation of the present climate, its modes of natural variability, and its recent evolution.
where are climate simulations especially challenged?
regional scale – the scale of relevance in adaptation efforts
what do climate models agree upon as of now?
further warming and other global and regional changes can be expected this century
what recent changes have been made to climate models?
higher resolution ones that can be used to project regional-scale changes
how can the destructive consequences of global climate change be moderated?(4)
by taking prompt actions to use energy more efficiently
transition to energy sources and products and services that do not release greenhouse gases
implement existing and novel technologies and practices to remove and store CO2 from the atmosphere
adapt to unavoidable changes
what are do the actions to moderate climate change involve?
involve individuals, communities, businesses, governments, acting at local, regional,
national, and global scales
what are the significant economic and social benefits that come from everyone working together against climate change?
better human health and well-being, employment opportunities, more
sustainably used resources, and conserved biodiversity
what is needed to achieve net-zero emissions?
enhanced co2 removal
what does solar radiation management require if used as a climate intervention approach?
cautious consideration of risks
shortcoming of enhanced CO2 removal and solar radiation management?
Neither can substitute for deep cuts in emissions or the need for adaptation
what will effective climate policies rely on?
innovative and responsive science and engineering to
inform and weigh response options
how must effective policies be discussed about regarding scientists?
Scientists and engineers must continue to engage with policy makers, communities, businesses, and the public to undertake solution-oriented research
and analysis
how must effective policies be discussed about regarding insitutions?
Scientific institutions, including academia and governmental agencies, should expand and prioritize their support for research, application, and knowledge dissemination to address the climate crisis
what is better than waiting and trying to catch up later in terms of climate change?
investing in adaptation
how is acting now a financially better decision?
the longer we wait, the more the costs will escalate
despite adapting seeming expensive, how is it a good thing?
we know a lot about how to adapt already as more is learned everyday
what have countries learned from CVID 19?
investing in adaptation
makes a lot more sense than waiting and trying to catch up later
globally a $… trillion investment in…. could generate..through what?
1.8; early warning systems, climate-resilient
infrastructure, improved agriculture, global mangrove protection along coastlines, and resilient water resources; $7.1 trillion through a combination of avoided costs and a
variety of social and environmental benefits
what effect does universal access have? universal access on what?
to early warning systems can
deliver benefits up to 10 times the initial cost
how could a would avoid a drop off in global agricultural yields? by how much?
if more farms installed solar-powered
irrigation, used new crop varieties, had access to weather alert systems and took other adaptive measures; up to 30% by 2050
