MAE 124
Food Bubble (Yemen)
"hydrologic basket case" and failed state
NCA4 Key Finding #2 (Chapter 2)
Aerosols caused by human activity play a profound and complex role in the climate system through radiative effects in the atmosphere and on snow and ice surfaces and through effects on cloud formation and properties. The combined forcing of aerosol-radiation and aerosol-cloud interactions is negative (cooling) over the industrial era (high confidence), offsetting a substantial part of greenhouse gas forcing, which is currently the predominant human contribution. The magnitude of this offset, globally averaged, has declined in recent decades, despite increasing trends in aerosol emissions or abundances in some regions (medium to high confidence).
Degradation of ecosystem services often causes significant harm to human well-being
All people depend on nature and ecosystem services to provide the conditions for a decent, healthy, and secure life.
Without significant reductions in emissions, average temperature increase by 2100 (relative to 1850- 1900) will be:
Between 2.6°-4.8°C
NCA4 Key Finding #3 (Chapter 4)
Beyond the next few decades, the magnitude of climate change depends primarily on cumulative emissions of greenhouse gases and aerosols and the sensitivity of the climate system to those emissions (high confidence). Projected changes range from 4.7°-8.6°F (2.6°-4.8°C) under the higher scenario (RCP8.5) to 0.5°-1.3°F (0.3°-1.7°C) under the much lower scenario (RCP2.6), for 2081-2100 relative to 1986-2005 (medium confidence).
Other GHGs
CO2 methane Nitrous Oxide
Countries with highest population
China, India, United States
Northwest China has rapid
Desertification
Radiative Forcing is the change in
Earths energy balance that will result in the climates cooling or warming
Food Bubble (Russia)
Excessive heat decreased wheat harvest in 2010
CO2 is longest lived
GHG most abundant
NCA4 Key Finding #4 (Chapter 1)
Global climate is projected to continue to change over this century and beyond. The magnitude of climate change beyond the next few decades will depend primarily on the amount of greenhouse (heat-trapping) gases emitted globally and on the remaining uncertainty in the sensitivity of Earth's climate to those emissions (very high confidence). With significant reductions in the emissions of greenhouse gases, the global annually averaged temperature rise could be limited to 3.6°F (2°C) or less. Without major reductions in these emissions, the increase in annual average global temperatures relative to preindustrial times could reach 9°F (5°C) or more by the end of this century (high confidence).
NCA4 Key Finding #4 (Chapter 4)
Global mean atmospheric carbon dioxide (CO2) concentration has now passed 400 ppm, a level that last occurred about 3 million years ago, when global average temperature and sea level were significantly higher than today (high confidence). Continued growth in CO2 emissions over this century and beyond would lead to an atmospheric concentration not experienced in tens of millions of years (medium confidence). The present-day emissions rate of nearly 10 GtC per year suggests that there is no climate analog for this century any time in at least the last 50 million years (medium confidence).
Earths Energy Budget
Greenhouse effect without GHGs, Earths average temperature would be -18C with natural GHGs, Earths average temperature would be 15C
There is soil erosion in
Haiti
Overpumping
Half the world's population lives in countries that are extracting groundwater from aquifers faster than it is replenished
Growth rate are ________ in developing countries
Higher
Negative impacts on crop yields
Higher temperatures will interfere with pollination, reduce photosynthesis and can dehydrate plants. Irrigation systems diminished by retreating mountain glaciers. Crop-shrinking heat waves will become more frequent and intense. Increasing frequency and intensity of extreme weather events.
NCA4 Key Finding #1 (Chapter 2)
Human activities continue to significantly affect Earth's climate by altering factors that change its radiative balance. These factors, known as radiative forcings, include changes in greenhouse gases, small airborne particles (aerosols), and the reflectivity of the Earth's surface. In the industrial era, human activities have been, and are increasingly, the dominant cause of climate warming. The increase in radiative forcing due to these activities has far exceeded the relatively small net increase due to natural factors, which include changes in energy from the sun and the cooling effect of volcanic eruptions. (Very high confidence)
NCA4 Key Finding #1 (Chapter 4)
If greenhouse gas concentrations were stabilized at their current level, existing concentrations would commit the world to at least an additional 1.1°F (0.6°C) of warming over this century relative to the last few decades (high confidence in continued warming, medium confidence in amount of warming).
Overplowing is happening in
In parts of Africa, Asia, and the Middle East, productive cropland is turning into wasteland
NCA4 Key Finding #3 (Chapter 1)
Many lines of evidence demonstrate that it is EXTREMELY LIKELY that human influence has been the dominant cause of the observed warming since the mid-20th century. Formal detection and attribution studies for the period 1951 to 2010 find that the observed global mean surface temperature warming lies in the middle of the range of likely human contributions to warming over that same period. We find no convincing evidence that natural variability can account for the amount of global warming observed over the industrial era. For the period extending over the last century, there are no convincing alternative explanations supported by the extent of the observational evidence. Solar output changes and internal variability can only contribute marginally to the observed changes in climate over the last century, and we find no convincing evidence for natural cycles in the observational record that could explain the observed changes in climate. (Very high confidence)
Fossil aquifers does
NOT replenish once its gone, its gone
Extracting water faster than it can replenish
Not sustainable (Yemen)
NCA4 Key Finding #2 (Chapter 4)
Over the next two decades, global temperature increase is projected to be between 0.5°F and 1.3°F (0.3°-0.7°C) (medium confidence). This range is primarily due to uncertainties in natural sources of variability that affect short-term trends. In some regions, this means that the trend may not be distinguishable from natural variability (high confidence).
Millennium Finding #1
Over the past 50 years, humans have changed ecosystems more rapidly and extensively than in any comparable period of time in human history. This has been driven largely to meet rapidly growing demands for food, fresh food, fresh water, timber, fiber and fuel. This has resulted in a substantial and largely irreversible loss in the diversity of life on Earth.
System Overload
Overfishing Overgrazing Overcutting Overplowing Overpumping
Total RF is
POSITIVE more energy is being absorbed by Earth than released back into space bc of Greenhouse effect
Ecosystem Services
Processes and functions of an ecosystem that benefit people directly and indirectly
Issues Lester says that impact food supply
Soil erosion and desertification Aquifer depletion Rising temperatures More frequent heat waves, droughts and floods
Greenhouse effect
Sun brings in solar radiation (70% absorbed by Earth, other 30% gets bounced back into space) Solar radiation is emited as infrared radiation from the Earth GHGs in atmosphere trap that radiation to warm the atmosphere
Millennium Finding #4
The challenge of reversing the degradation of ecosystems while meeting increasing demands for their services can be partially met under some scenarios that the MA considered but these involve significant changes in policies, institutions and practices, that are not currently under way Many options exist to conserve or enhance specific ecosystem services in ways that reduce negative trade-offs or that provide positive synergies with other ecosystem services
Millennium Finding #2
The changes that have been made to ecosystems have contributed to substantial net gains in human well-being and economic development. But these gains have been achieved at growing costs -Degradation of ecosystem services -Increased likelihood of nonlinear changes -Exacerbation of poverty for some people Poor people, particularly those in rural areas in developing countries, are more directly dependent on biodiversity and ecosystem services and more vulnerable to their degradation. These problems, unless addressed, will substantially diminish the benefits that future generations obtain from ecosystems.
Millennium Finding #3
The degradation of ecosystem services could grow significantly worse during the first half of this century and is a barrier to achieving the Millennium Development Goals*.
NCA4 Key Finding #2 (Chapter 1)
The frequency and intensity of extreme heat and heavy precipitation events are increasing in most continental regions of the world (very high confidence). The frequency and intensity of extreme high temperature events are virtually certain to increase in the future as global temperature increases (high confidence). Extreme precipitation events will very likely continue to increase in frequency and intensity throughout most of the world (high confidence). Observed and projected trends for some other types of extreme events, such as floods, droughts, and severe storms, have more variable regional characteristics.
NCA4 Key Finding #1 (Chapter 1)
The global climate continues to change rapidly compared to the pace of the natural variations in climate that have occurred throughout Earth's history. Trends in globally averaged temperature, sea level rise, upper-ocean heat content, land-based ice melt, arctic sea ice, depth of seasonal permafrost thaw, and other climate variables provide consistent evidence of a warming planet. These observed trends are robust and have been confirmed by multiple independent research groups around the world. (Very high confidence)
Overgrazing
The global grazing livestock population grew by 1.2 billion animals since 1960
NCA4 Key Finding #3 (Chapter 2)
The interconnected Earth-atmosphere-ocean system includes a number of positive and negative feedback processes that can either strengthen (positive feedback) or weaken (negative feedback) the system's responses to human and natural influences. These feedbacks operate on a range of time scales from very short (essentially instantaneous) to very long (centuries). Global warming by net radiative forcing over the industrial era includes a substantial amplification from these feedbacks (approximately a factor of three) (high confidence). While there are large uncertainties associated with some of these feedbacks, the net feedback effect over the industrial era has been positive (amplifying warming) and will continue to be positive in coming decades (very high confidence).
NCA4 Key Finding #1 (Chapter 3)
The likely range of the human contribution to the global mean temperature increase over the period 1951-2010 is 1.1° to 1.4°F (0.6° to 0.8°C), and the central estimate of the observed warming of 1.2°F (0.65°C) lies within this range (high confidence). This translates to a likely human contribution of 93%-123% of the observed 1951-2010 change. It is extremely likely that more than half of the global mean temperature increase since 1951 was caused by human influence on climate (high confidence). The likely contributions of natural forcing and internal variability to global temperature change over that period are minor (high confidence).
NCA4 Key Finding #2 (Chapter 3)
The science of event attribution is rapidly advancing through improved understanding of the mechanisms that produce extreme events and the marked progress in development of methods that are used for event attribution (high confidence).
Overcutting
The world's forests lose a net 5.6 million hectares—an area the size of Costa Rica—each year
Radiative Forcing measured in
W/m^2
Ecosystem impacted by human activities
Worsening soil erosion desertification
Greenhouse effect is
a natural process wouldn't be able to live without it
Anthropogenic aerosols
absorb and reflect heat and energy warm earth
Ecosystem impact (Desertification)
advancing deserts in Asia and Africa
Ecosystem Services (Cultural)
aesthetic, spiritual, educational, recreational
Saudi Arabia is extracting
all of fossil aquifers loosing water
fossil aquifer
are large underground reserve of water that were established under past climatic and geological conditions
Over the next two decades, global temperature increase is projected to be
between 0.3°-0.7°C
Ecosystem Services (Regulating)
climate regulation, flood regulation, disease regulation
if greenhouse gas concentrations were stabilized at their current level, existing concentrations would
commit the world to a least and additional 0.6 °C of warming.
Food Bubble (Saudi Arabia)
depleted its fossil fuels can no longer grow food
Browns three key social, economic, and political indicators
economic -global price of food rising (grains) social -rate of hunger around the Earth Political -number of failing states
Desertification
fertile land becomes desert from drought, deforestation, inappropriate agriculture
Controlling soil erosion is a
food security solution according to Lester Brown
Ecosystem Services (Provisioning)
food, freshwater, wood, fiber, fuel
Brown connects failing states by
food, water, land -eroding soils (China and Africa) -water, food scarcity
Aquifer
groundwater replenishable
Anthropocene starts
in the industrial revolution
Earth is warming the most
in the north
Largest contribution of total RF is
increased concentration of CO2
These land acquisitions are an
integral part of a global power struggle for control of the earth's land and water resources.
unsustainable aquifers in Yemen
is a problem
Growth rate are ________ in developed countries
lower
Aerosols
mist of small particles can be natural or anthropogenic
Ecosystem Services (Supporting)
nutrient cycling, soil formation, primary production
Radiative forcing is the difference
of sunlight absorbed by Earth and sunlight Earth is reflecting back into space
Food Bubble
pump up production by burning through unsustainable resources (crop and water)
Aquifer can be replenished by
rainfall
Food Bubble (Arab Middle East)
region with fast growing population and decreasing water supplies
Kneeling Curve is the
single indicator for tracking the progression of anthropecene (units in ppm)
Biodiversity is
the foundation of ecosystem services to which human well-being is intimately linked.
Biodiversity is projected
to DECREASE in the future due to the effect of additional CO2 in atmosphere
Soil erosion
wearing away of surface soil by water and wind
Three things used to determine Earths temperature
-Albedo (solar radiation reflected) -Incoming solar radiation -Concentration of GHGs in atmosphere
Aerosols contribute to
-Cloud formation (absorb heat and scatter light back into atmosphere) Responsible for both warming and cooling
Lesters 4 main goals
-Cut CO2 emissions by 80% by 2020 -Stabilize population at or below 8 billion by 2040 -Eradicate poverty (bringing up least developed countries) -Restore earths natural system (Forests, soils, aquifers, fisheries exploiting them faster then they can be replenished)
Human activities that impact Radiative Forcing
-GHGs concentration -amount of aerosols put into air -changes in albedo
Causes of CO2 increasing in atmosphere
-burning of fossil fuels (main reason) -deforestation (no trees to take out CO2, no CO2 taken out, Earth gets warmer) -soil degradation (reduces productivity)
Aerosols ( anthropogenic)
-car exhaust -industrial process -smoke from wild fires
Aerosols (Natural)
-fog -dust -volcanic eruptions (geoengineering to throw Sulfur in air to decrease temperature)
Trends of global population growth
-global population is increasing -rate of growth is decreasing
Human endeavors human have impacted the environment (examples how humans have induced change)
-high percentage for fisheries exploited -CO2 increasing in atmosphere -Flood frequency increasing -Increasing N2O -increasing CH4 -Increasing Ozone depletion -Increasing Northern Hemisphere Average Temperature -Increasing Loss of rain, forest, woodland -Increasing in domesticated land -increasing in global diversity
Ecosystem impact (Worsening soil erosion)
-over plowing, overgrazing -1/3 of world's cropland is now losing topsoil faster than it can be re-formed -Topsoil loss reduces productivity, eventually leading farmers and herders to abandon their land -Countries such as Lesotho, Haiti, Mongolia, and North Korea are losing the ability to feed themselves taking away possibility of providing food (especially for developing countries)
Representative Concentration Pathways (RCPs)
-pathways of 4 possible climate future that will be experienced if humans do nothing at all (Business as usual) or take certain steps -modeling scenario
Ensure future well being of humanity
-putting a price on carbon, ecosystem services -valuing nature -more education
Keeling Curve (What is it, what does it do?)
-shows increasing CO2 over time - -humans burning fossil fuels is the reason for rapid increase of CO2
NCA4 trends
-temperatures are warming (already warmed 1 degree celsius) -wet areas are getting wetter -dry areas are getting dryer -snow and ice are melting -sea level is rising (already risen 20-23 cm)
5 current drivers for biodiversity loss
1. Habitat loss 2. Overexploitation (overfishing, overharvesting) 3.Invasive Species 4. Pollution 5. Climate Change
Millennial Ecosystem Assessment
1. How have ecosystems and their services changed? 2. What has caused these changes? 3. How have these changes affected human well-being? 4. How might ecosystems change in the future and what are the implications for human well-being? 5. And what options exist to enhance the con-servation of ecosystems and their contribution to human well-being?
Ecosystem Services 4 broad categories
1. Provisioning 2. Regulating 3. Cultural 4. Supporting
industrial revolution
1800-1945 Large scale CO2 emissions start of industrial revolution Human population expands
Age of acceleration
1945-2015 starts after WW2
Current CO2 concentration
400 ppm
Overfishing
80% of oceanic fisheries are being fished at or beyond their sustainable yield
