Module 8Part III

The Forecast

The Smoking GunChapter 11

Climate forcings: changes in some parts of the Earth’s energy budget that affects the temperature of the Earth

Look at the past, (models are changing to agree with the experimental data for past climate)

Predict the future

Is the Globe Warming?

Land and sea (different heat capacities) temperatures are recorded separately

“Urban heat island effect” cities are warmer by about 5 °C from sunlight absorbed by pavement (sensible heat), the heat is emitted at night

“Countryside” sunlight hits land, water evaporates and contains latent heat, latent heat releases as water condenses

Thermometer Records

Removing urban temperatures from the

models has only a small effect, the result – the planet is still warming

Model results:

Records changed in 1942 <1942, a wood or canvas bucket provided

some cooling, and were thrown at various depths.

>1942 the SST was measured in the engine room as cooling water entered the engine room.

The sea surface temperature agrees with the land, the Earth’s surface is warming

Surface Sea Temperature (SST)

The agreement between the land and the sea

temperatures warming are based on thousands of

locations globally, and not by “cherry picking” only

selected areas.

Results:

Measures oxygen molecules in the rotational mode, they emit microwave radiation, which is a longer and lower energy wave than infrared.

Temperature estimates from satellites used to disagree with the thermometer reading on the ground, but this was caused by errors in data processing that have now been fixed

Is this a problem?

Satellite measurements for temperature

Measurements are made from a series of satellites

They are all calibrated against each other

Raw data is corrected for things like changes in the orbit of the satellite

Satellites are ideal for global “snapshots”

Satellite measurements

Glaciers are melting, and they are routinely monitored and measured

Another confirmation that the Earth is warming

Visual Indicators

Climate forcings are different factors that can change the climate

The comparison is the effect on the Earth’s energy budget (W/m2)

The radiative forcing in W/m2 allows us to compare the causes of climate change on a roughly equal footing

Climate Forcings

The state variable is W/m2

These changes include:◦Solar variability◦Greenhouse gasses◦Anthropogenic aerosols◦Volcanic particulate emissions to the atmosphere

Changes in climate forcings

The energy imbalance immediately after the change happened, but before the

climate responds to the change

Chapter 4 – the climate sensitivity benchmark was the CO2 doubling, ΔT2X

Earths temperature rises in proportion the number of CO2 doublings, the estimate is 3°C

Radiative Forcing

Chapter 11 – the climate sensitivity parameter relates the equilibrium warming

to the radiative forcing

ΔTR ~ 0.75 / W/m2

~ 1.5 W / m2

New version

Have the climate forcings changed with time? Solar intensity:

◦ Measured by satellite◦ No atmospheric interference◦ Data collection since 1975◦ The sun has an eleven year sunspot cycle◦ <1975, observations in the sunspot cycle for about

400 years◦ Also measured in ice cores, checking the ratio of

cosmogenic isotopes Be-10, and C-14◦ Weaker sun, less cosmic ray deflection, more

isotopes

Climate forcings: Changes with time

Maunder Minimum, 1650 – 1700A period of no sunspotsColdest period in Europe in the last 1000 years

Climate anomalies

If the eruption is strong enough, it can send particulate into the stratosphere and cool the planet for several years

Mt. Pinatubo in the Philippines erupted in 1991

1900 – 1950, the temperature rose 1950 – 1970, the temperature declined 1970 – present time, the temperature is

rising

Volcanic Eruptions

Intergovernmental panel on climate change, had their meeting in Warsaw last month

The 2007 assessment report: 19 models were run twice using the same

scenarios They were run with human contributions,

and they were run without human contributions

With human contribution, the model simulates the temperature increase since 1970

United Nations - IPCC

The smoking gun for global warming is the rise in temperature since 1970

The models can’t reproduce the temperature change that has been measured without considering the human contribution of greenhouse gasses to the atmosphere

The Smoking Gun

1. There would have to be some other way to explain the recent warming since 1970

2. There would have to be a reason to throw out the greenhouse effect theory – or – explain why increasing CO2 would not block outgoing IR energy by absorbing the IR in its vibrational energy mode

What would it take for the Global Warming Forecast to be wrong?

No thermometers for most of the period, must be determined by proxy measurement

Look at the thickness of annual tree ring layers in the wood

Bore holes for surface temperature proxy measurements

Condition of ice sheets and mountain glaciers

Climate of the last millennium

There was a warm period from 800 – 1200, called the Medieval Climate Anomaly

There was a cold period from 1350 – 1800, called the Little Ice Age

The Little Ice Age corresponded to the Maunder Minimum, a period of no sunspots

Result – Natural Variability

Last Glacial Maximum was 18,000 years ago Continents were covered in massive ice

sheets There was a polar amplification, high

latitudes felt more of an effect than the tropics

The atmosphere had less CO2 and CH4

Ice, ice sheets, sea ice and snow changed Earth’s albedo

Further back:

55 million years ago, Paleocene, Eocene Thermal Maximum

The ratio of C-12 / C-13 in deep ocean CaCO3 sediments indicated that there was a sizeable release of C to the atmosphere or the ocean

The early release is an analogy to the fossil fuel CO2 release

And from the deep past

As with the Last Glacial Maximum, it will be many thousands of years for temperatures to recover to their natural baseline values

after a sizeable CO2 release

But what is the natural baseline temperature value?

Result?

The past few years have been warmer than the thermometer records of the past 140 years and warmer than reconstructed records over the past 1,000 years

Climate change is driven by natural and human-induced changes in radiative forcing, including volcanic eruptions, solar variability, greenhouse gases, and human released aerosols.

Take home points, Chapter 11

Models cannot explain the rise in global temperatures since about 1970 without including anthropogenic forcing. This is the smoking gun for a human impact on climate.

Continued…

Potential Climate Impacts

Chapter 12

Drought and storms, and sea

level, not just the warming

IPCC

Climate Central

Websites

GRACE – Gravity Recovery and Climate Experiment (March 2002, failed in 2011)

NASA's gravity field satellite mission GRACE has provided nine years worth of data about changes in Earth's gravity field. The analysis of the data from the two satellites on the mission was published in the Nature Geoscience Journal, which looks at the melting of our Earth's ice sheets.

Twin dedicated satellites

ICESat – Ice, Cloud and Land Evaluation Satellite (January 12, 2003, 3rd laser failed 2010)

ICESat, part of NASA's Earth Observing System, was a satellite mission for measuring ice sheet mass balance, cloud and aerosol heights, as well as land topography and vegetation characteristics. Wikipedia

After seven years in orbit and 18 laser-operations campaigns, the ICESat's science mission ended due to the failure of its primary instrument. http://nsidc.org/data/icesat/

Another satellite

Warmer temperatures are not going to be the most important thing to affect people.

There will be more impact from:◦ Drought◦ Storms◦ Regional rather than global effects

The Warming Itself

Temperature rise from 1 – 6 °C

Big range, why the uncertainty? Two reasons:

1. What is the temperature response to additional CO2?

2. How much CO2 will be released?

IPCC predicts

Changes in rainfall patterns and amounts Changes in a few degrees changes the

landscape Comparison to the last ice-age, global

temperatures were 5-6 ° cooler – huge impact!

Europe and North America were covered in huge ice sheets

Pollen data shows huge changes in vegetation

Main Impact

Changing climate caused the demise of two classical civilizations

The Mayan and the Anasazi civilizations collapsed in several stages that correlated with strong, decades long droughts.

History shows the impacts

High latitudes are warming fasterPermafrost melts, collapsing the soil

Houses and trees tiltLakes disappear

Global warming is not globally uniform

1995 Chicago 1999 Mid Atlantic area Europe 2003 (France) 100 year event? Happened again in 2006 2010 Russia 2011 Texas 2012 “summer in March” in the US Midwest Many more, causing very high heat related

morality rates

Extreme heat events

CDC document on heat events

Extreme heat events

Heat is the most lethal type of weather phenomenon

High mortality Psychological stress (higher crime rates) Power outages Wildfires Physical damage

◦ Softening pavement◦ Buckling railroad tracks◦ Burst water lines◦ Power transformers detonating

Health Effects

Changing climate rearranges weather patterns and water supplies that are difficult to forecast

Hadley circulation – expected to increase in a warmer climate, intensifying rainfall at the equator and causing further drying in the desert regions.

Projection for monsoons in South China and India to become stronger and stormier

Emergent Effects

Droughts driven by a change in the water pattern are expected to increase, particularly in:◦ American Southwest◦ Mediterranean◦ Australia

The loss of plants amplifies the drought and also makes it harder to break out of a drought.

The carrying capacity of the land depends on rainfall.

More effects…

But not uniformly! The tropical cyclones are predicted to be

stronger and more frequent The storm seasons have not validated this

prediction In fact, the hurricane season that ended last

weekend was the mildest storm season since 1982

Warmer = Wetter

Rising sea level – the change is slow, and seas will continue to rise for centuries, for two reasons:

1. Thermal expansion of water (0.5-2.0 m)

2. Melting ice on land, glaciers and ice sheets

Ice and Sea Levels

Floating ice, sea ice, and ice shelves do not increase sea level when it melts because the ice already displaces its own weight in water

Archimedes Principle – when floating ice melts, its water exactly fills the hole that the ice had previously occupied.

Archimedes Principle

The ice sheets in Greenland and Antarctica are the slow giants contributing to the rise in sea level.

Together they could raise sea level by 70 m 70 m = 230 feet The elevation of St. Leo is 167 feet Sea level could rise as high as a mid-rise, 14

story hotel on Miami Beach Florida’s highest elevation is 345 feet

Giant Ice Sheets

Ice shelves collapse abruptly, no way to add this into the models

In 2002, Larsen Ice Shelf took a few months for an area the size of Rhode Island to collapse into ice bergs

When the ice collapses, or melts, the land usually rises! The weight of the ice is gone and the crust lifts slightly higher in elevation

IPCC forecast for 0.5-1.0 m increase is totally unrealistic

Ice Shelves

Occasionally there is a flip-flop of climate Change occurs over a few years, but may

last for centuries Presently, the Holocene Period, the climate

has been stable for the last 10,000 years 20,000 – 80,000 years ago there were 1,000

year temperature swings called Dansgaard-Oeschger Events

Sudden warming of 10-15°C in a few years followed by gradual cooling

Most intense in the high Northern latitudes

Abrupt Climate Change

The land surface depends on the local climate

Includes temperature, precipitation, and the human footprint (agriculture, decorative lawns, and pavement)

Insects move easily; trees do not

Biological Impacts of climate change

The Arctic, polar bear habitat may be restricted to the northern parts of Greenland

The tropical oceans, coral reefs are particularly sensitive to pollution in runoff and changes in temperature

Corals respond to stress by “coral bleaching”

Symbiotic algae are ejected, and coral reefs soon die

Largest impact?

The climate change will amplify the extinction trends by demanding that natural

ecosystems get up and move, just when they are restricted by human land use and least

able to do so.

Species are declining

Changes in water availability

Melting mountain glaciers and snowpack are a summertime source of drinking water in:

Himalayas, for India, Pakistan, Uzbekistan Andes, for Lima, La Pas, Quito North America, in the Pacific Northwest

Human Impacts

The growers may have to change crops to meet the changing conditions

Presently, the world food production is greater that consumption – can it continue?

Agriculture

There is a concern about tropical diseases spreading with the warmer climate

Impacts will be stronger in the tropics and developing nations where there is less wealth to buffer setbacks from the weather and less infrastructure to deal with the aftermath.

Health Impacts

Climate models that simulate the past predict huge climate changes in the future, relative to what civilized humanity has ever seen before.

Drought is one of the most dangerous aspects of climate change, as continental interiors warm and dry out, despite a global increase in the amount of rainfall overall.

Extreme weather events are already getting stronger and this trend is expected to continue.

Take home points, Chapter 12

Sea level will continue to rise for centuries from thermal expansion and melting land ice.

Continued…

Decisions, DecisionsChapter 13

Tragedy of the Commons, the moral is that everyone would be better off if they co-operated!

A cost that is not paid by the decision maker is called an external cost.

The cost of climate change is not only paid by people who are responsible but by everyone, soon, and far into the future.

Global Warming is a Large Scale Problem

A regulatory agency allocates permits for emission of climate forcing agents such as CO2

The total number of permits they issue is a lower overall rate of emission

If a company has lower emissions than the permit allows, it can sell its allocation as carbon offsets

Companies already exist whose function is to sell carbon offsets, using the money to find ways of cutting carbon dioxide emissions

Cap and Trade Scheme

Carbon tax and cap and trade accomplish the same things in the end

The tax specifies the price and allows the market to choose the emission, whereas the cap and trade sets emissions and lets the market choose the price

Local issues, easy to solve Regional issues tend to be us vs. them Global warming is the most global of issues

and the most complicated type to solve

Carbon tax solution

1988, agencies of the U.N. formed the IPCC

Their role is to assess “the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation.”

Purpose is to publish reports summarizing the scientific literature

Negotiations

WGI – deals with the scientific basis for the climate change forecast

WGII – deals with the impacts of climate change on the natural and human world

WGIII – assess options for limiting greenhouse gas emissions or otherwise avoiding climate change

Three working groups

Consist of chapters and various levels of summaries

1990, the first IPPC report was that it was not yet possible to detect human-induced global warming (models left out human induced aerosols and changes in solar intensity)

1995, the second report fixed the models, and issued the now famous statement that “the balance of evidence suggests a discernable human influence on global climate.”

The Reports -

As a result, a 1997 meeting in Kyoto, Japan drafted the Kyoto Protocol which attempted to limit global CO2 emissions to about 6% below 1990 emission levels by the year 2010

The treaty cam into force when countries accounting for 55% of the emissions agreed to the terms

U.S. withdrew under the Bush administration in 2001

Russia agreed in 2005, putting the agreement into force without the U.S.

Kyoto Protocol

The agreement has no “teeth” The rate of CO2 emission has grown rather

than decline Kyoto Protocol due to expire in 2012 “Only two things are clear after the climate

meeting in Doha, Qatar: a weak Kyoto Protocol will remain in place for a few more years and more negotiations are needed”

http://www.scientificamerican.com/article.cfm?id=climate-conference-renews-kyoto-protocol-but-looks-to-successor

In Practice?

The Montreal Protocol on Substances that Deplete the Ozone Layer was adopted in 1987 as an international treaty to eliminate the production and consumption of ozone-depleting chemicals.(www.worldbank.org)

The agreement to limit CFC emission to the atmosphere to save the ozone in the stratosphere has done more to slow global warming than the Kyoto Protocol

Interesting fact

The economy is much harder to forecast than the weather, otherwise we would all be wealthy

More and cheaper CO2 emission cuts are possible in the next few decades from improvement in energy efficiency that from new alternative energy sources

Costs of avoiding climate change would be comparable to the costs of deciding to go to war - significant, but not prohibitive

Economics

Goal of IPCC, “to prevent dangerous anthropogenic interference with the climate system” (lacks definition)

Accepted benchmark target is 2°C Earth has been warmer – probably 400,000

years ago when the Earth resembled today, a time called Stage 11 (look at fig.8-4)

>2°C isn’t really a danger limit, but surpassing it makes the projected damages go up rather drastically

Dangerous Anthropogenic Interference

How fast is the climate going to change? IPCC says that the warming should be slow

enough for ecosystems to adapt naturally, with no threat to food production, and to enable economic development to proceed in a sustainable manner

In other words – the transition to a new climate regime should be slow enough for

natural and human systems to adapt.

Another issue…

The greatest short term solution is conservation

Most of the cheapest solutions involve energy efficiency rather than new energy sources.

Nuclear energy generates no carbon, and we know it works, but the Uranium is in short supply

Converting U to Pu, increasing the yield 50x Downside, Pu is also a weapons-grade

radioactive element-not everyone wants

Alternatives

Windmills

Very clean alternative, and not so unattractive!

They supply 7% of Denmark's power, and 0.3% of the global energy.

It’s growing by 30% a year, scaling up the production by 50x would generate about 2 TW of energy.

Solar thermal, lower tech, concentrate sunlight with mirrors to heat water, generate steam, turn a turbine and generate electricity

Photovoltaic uses semi-conductor technology, it’s very expensive, but doable.

Generally, no one solution exists, it will need to be a combined effort, or a new technology that doesn’t exist yet.

Solar

It’s very easy to produce hydrogen from water, but it requires electricity

Hydrogen can be produced from the gasification of coal – probably messy

Requires a pressurized container

Extremely flammable

Hydrogen

CO2 sequestration

Most countries are not capturing carbon dioxide emissions and storing them underground, because the process is expensive.

A closed-loop system that injects CO2 into hot brine brought to the surface from deep underground could make CO2 storage economical by providing geothermal energy and methane for fuel. The CO2-laden brine would be sent back down for permanent storage.

Calculations show that enough deep brine exists along the U.S. Gulf Coast to store one sixth of the country's CO2 emissions and to meet one sixth of its demand for natural gas annually.

In Brief:

When oceanographers add iron to the Southern Ocean, the plankton bloom – they are primary producers

The idea is that the plankton would grow, die, and sink to the deep ocean, taking the carbon with them

Ocean Fertilization

Generate a haze in the stratosphere by releasing sulfur of some other chemical

Aerosols cool the Earth by scattering sunlight

Putting particles in the stratosphere is that no rain originates there, so the injected aerosols would remain for several years

Shoot sulfur in canisters from large cannons Or just put sulfur in jet fuel and let the air

traffic do the job

Geoengineering

Human-induced climate change is an example of the tragedy of the commons. Economists refer to climate change as an external cost, which can cause the market to make poor decisions. Economic forces also keep the market focused on short-term profit and cost, disregarding costs that come far in the future.

International negotiations under the auspices of the United Nations have not made much progress so far in actually reducing GHG emissions.

Take home points, Chapter 13

The ultimate goal of negotiations is to prevent “dangerous interference” with the climate system. Danger, in this context, might be benchmarked in terms of global temperature, rate of warming, sea-level rise, peak atmospheric CO2 concentration, or the total amount of CO2 ever released.

The sooner we begin changing the energy infrastructure, the cheaper it will be to avoid dangerous climate change.

Continued…