Module 1 Climate Change

Science

Climate change, the science The Science The Greenhouse Effect The Science The Earths cycles The Laws of Thermodynamics How it all relates Projections Result Further Reading

Topics

There is often confusion between weather and climate.

Weather is the condition of the atmosphere at a particular place over a short period of time.

Climate refers to the weather pattern of a place over a long period, maybe 30 years or more, long enough to yield meaningful data.

Weather and Climate

Therefore a weather change is an afternoon storm rolling in to Brisbane.

Where as Climate Change refers to major changes in temperature, precipitation, or wind patterns, among others.

Resulting in Brisbane getting some welcome rain as opposed to sea level rise, severe weather events more often, drought and flooding, plus many more.

Weather and Climate

Greenhouse gases naturally blanket the Earth and keep it roughly 33C warmer than it would be without these gases in the atmosphere.

This is called the Greenhouse Effect. It is also a natural process. Same principle as a greenhouse.

Greenhouse Gases are predominantly made up of Water Vapour (H2O), Carbon Dioxide (CH2), Methane (CH4), and Nitrous Oxides (NOx), there are others.

Climate Change Science

The most Common GHGs in order are: Water vapor (H2O), Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), Ozone (O3) and CFCs.

Human activity has increased the concentrations of GHGs in the atmosphere, particularly since 1800s, Industrial Revolution

Activities such as burning of fossil fuels (Coal and Oil for energy), land clearing, agriculture and manufacturing, all add to the production of GHGs.

The natural processes of the Earth have not been able to keep up with the enhanced GHG production.

The result, a build up of GHG in the atmosphere, leading to a gradual increase of the Earths temperature.

Climate Change Science

Compound FormulaContribution

(%)

Water vapour and clouds H2O 36 72%

Carbon dioxide CO2 9 26%

Methane CH4 49%

Ozone O3 37%

Concentrations of common GHGs

The Greenhouse Effect

Under normal circumstances solar radiation passes through the atmosphere.

Some radiation is reflected by the atmosphere, the rest is absorbed by processes on earth, plants, seas, oceans, etc. What is not used is reflected back.

Climate Change scenario relates to a layer of greenhouse gases building up in the atmosphere. This layer reflects any escaping radiation back to earth rather than letting it escape and slowly warms up the atmosphere underneath hence the term global warming.

From the previous slide we understand that under normal circumstances solar radiation enters our atmosphere, interacts with Earths processes and whatever is not used gets reflected back through the atmosphere in to space.

However, a build up of GHG in the atmospheric layers decreases the amount of solar radiation reflected back, effectively trapping it in our system. Consequence global warming.

Science

Most scientists believe Global Warming is definitely happening.

Others believe it to be part of the natural processes of the Globe. Which is true to an extent.

United Nations Framework Convention on Climate Change, UNFCCC.

Intergovernmental Panel Climate Change, IPCC. Everyone else seems to be slowly coming around.

Divided Opinions

UNFCCC - In 1992, countries joined an international treaty, the United Nations Framework Convention on Climate Change, to cooperatively consider what they could do to limit average global temperature increases and the resulting climate change, and to cope with whatever impacts were, by then, inevitable.

IPCC - The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for the assessment of climate change. It was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) in 1988 to provide the world with a clear scientific view on the current state of knowledge in climate change and its potential environmental and socio-economic impacts. In the same year, the UN General Assembly endorsed the action by WMO and UNEP in jointly establishing the IPCC. The IPCC is a scientific body under the auspices of the United Nations (UN). It reviews and assesses the most recent scientific, technical and socio-economic information produced worldwide relevant to the understanding of climate change. It does not conduct any research nor does it monitor climate related data or parameters.

In May 1982 the Intergovernmental Agreement on the Environment formed the idea of the Precautionary Principle.

By definition it states: Where there are threats of serious or irreversible

environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation.

The Precautionary Principle

The first endorsement of the principle was in 1982 when the World Charter for Nature was adopted by the United Nations General Assembly, while its first international implementation was in 1987 through the Montreal Protocol. Soon after, the principle integrated with many other legally binding international treaties such as the Rio Declaration and Kyoto Protocol.

In application of the precautionary principle, public and private decisions should be guided by:

1. Careful evaluation to avoid, wherever practicable, serious or irreversible damage to the environment; and,

2. An assessment of risk-weighted consequences of various options.

It should be noted that in this application the idea of Environmental Impact Assessments was born.

The Precautionary Principle

Dr. Robert Watson, 2001 Chairman of the IPCC, has stated, at the 3rd meeting:

" The overwhelming majority of scientific experts, whilst recognizing that scientific uncertainties exist, nonetheless believe that human-induced climate change is already occurring and that future change is inevitable."

Application of the precautionary principle

IPCC Statement

However, scientific evidence at present is fairly certain that human activity has placed pressure on the natural processes in assimilating excess GHGs, more than ever before.

So the sceptics are falling by the wayside and evidence is showing what we have believed and thought for the past 3 decades in relation to climate change.

Scientific Evidence

The human processes that cause a speeding up of the GHG concentrations include: Burning of fossil fuels for energy oil, gas, coal etc. Deforestation clearing the land of trees and forests to

make way for agriculture. Removing carbon sinks. Manufacturing processes that use or produce certain

chemical compounds that are GHGs such as magnesium smelting using sulphur hexafluoride.

Human Activity

Sulphur hexafluoride - Sulphur hexafluoride (SF6) is an inorganic, colourless, odourless, non-flammable, extremely potent greenhouse gas which is an excellent electrical insulator.

According to the Intergovernmental Panel on Climate Change, SF6 is the most potent greenhouse gas that it has evaluated, with a global warming potential of 23,900 times that of CO2.

"Each passing day brings yet more evidence that we are now facing a planetary emergency a climate crisis that demands immediate action to sharply reduce GHG emissions worldwide in order to turn down the earths thermostat and avert catastrophe.

"The serious debate over the climate crisis has now moved on to the question of how we can craft emergency solutions in order to avoid this catastrophic damage."

Al Gore.

An Inconvenient Truth

World Temperatures

20 hottest years on record Reliable instruments have been used since

1880 to determine patterns in climate, ice cores from Antarctica show patterns over the centuries.

19 of the top twenty hottest recorded years have been in the last 25.

2005 and 1998 were almost identical in data, yet 1998 was a very strong El Nino year, 2005 was very weak El Nino at the start of the year, and normal conditions the remainder.

GHG Concentrations

These figures show that the atmospheric concentrations of the key anthropogenic greenhouse gases, carbon dioxide, methane and nitrous oxide were constant over hundreds of years until the industrial era. The observed increases in the atmospheric concentrations carbon dioxide, methane and nitrous oxide of 33%, more than a factor of two, and about 15% are attributable to human activities. Similarly, the atmospheric concentration of sulfate aerosols started to increase in the late 1800s due to the combustion of coal.

The Climate System

A climate cycle is any recurring cyclical oscillation within global or regional climate, and is a type of climate pattern. These fluctuations in atmospheric temperature, sea surface temperature, precipitation or other parameters can be periodic, often occurring on inter-annual, multi-annual, decadal, multidecadal, century-wide, millennial or longer timescales.A prominent example is the El Nio-Southern Oscillation, involving sea surface temperatures along a stretch of the equatorial Central and East Pacific Ocean and the western coast of tropical South America, but which affects climate worldwide. Also known to produce El-Nino and La Nina climate cycle events. An El Nino event brings drought to the eastern parts of Australia while a La Nina brings more than normal rain patterns and often flooding.Records of past climate conditions are recovered through geological examination of proxies, found in glacier ice, sea bed sediment, tree ring studies or otherwise.

Global Energy Balance

Earth's Energy balance describes how the incoming energy from the sun is used and returned to space. If incoming and outgoing energy are in balance, the earth's temperature remains constant.Essentially 100% of the energy that fuels the earth comes from the sun. To maintain a constant global average temperature, all of the suns radiation that enters Earths atmosphere must eventually be sent back to space. This is achieved through Earths energy balance. The above slide depicts how the energy from the sun is absorbed, reflected, and emitted by the earth.

The Water Cycle

Water covers about three-quarters of Earth's surface and is a necessary element for life. During their constant cycling between land, the oceans, and the atmosphere, water molecules pass repeatedly through solid, liquid, and gaseous phases (ice, liquid water, and water vapour), but the total supply remains fairly constant. A water molecule can travel to many parts of the globe as it cycles.

The Carbon Cycle

The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. Along with the nitrogen cycle and the water cycle, the carbon cycle comprises a sequence of events that are key to making the Earth capable of sustaining life; it describes the movement of carbon as it is recycled and reused throughout the biosphere.

In essence, all of the Earths cycles as explained on the previous slides have one thing in common: That the amount of energy, water, carbon, nitrogen,

hydrogen, in fact all natural resources containing any of these elements are at any one time in balance.

Meaning that the amount of each resource within the whole of the cycle is relatively the same.

This relates to the Laws of Thermodynamics.

The Global Cycles

Energy exists in many forms, such as heat, light, chemical energy, and electrical energy. Energy is the ability to bring about change or to do work. Thermodynamics is the study of energy.

If we go one step further we can say that ALL resources and processes behave the same way as energy when we relate the Laws of Thermodynamics to them.

The Laws of Thermodynamics

The first law of thermodynamics is often called the Law of Conservation of Energy. This law suggests that energycan be transferred from one system to another in many forms. However, it can not be created nor destroyed. Thus, the total amount of energy available in the Universe is constant. Einstein's famous equation describes the relationship between energy and matter:

E = MC2

Einstein suggested that energy and matter are interchangeable. His equation also suggests that the quantity of energy and matter in the Universe is fixed.

Defined - The First Law

Energy, matter, resources etc are never destroyed or created. They simply transfer from one state to another.

Burn Coal, you get heat that boils water, to get steam that turns turbines that cause friction and create electricity.

The electricity is used down the line to run appliances, heat water and light your home.

The energy is moved from one state to another, but never destroyed.

The First Law (Simplified)

Energy can never pass spontaneously from a colder to a hotter body. As a result of this fact, natural processes that involve energy transfer must have one direction, and all natural processes are irreversible. This law also predicts that the entropy of an isolated system always increases with time. Entropy is the measure of the disorder or randomness of energy and matter in a system. Because of the second law of thermodynamics both energy and matter in the Universe are becoming less useful as time goes on.

Defined - The Second Law

Once the transfer of energy has occurred it can not be recovered the same way.

For example, a frying pan on a stove will heat from the gas being burnt underneath, that heat will cook the food, to eat.

However, leaving the frying pan on the stove, the energy lost through the transfer of heat will not return from the atmosphere or the food back to the pan, back to the flame.

Entropy.

The Second Law (Simple)

Therefore, we can relate the laws of thermodynamics to all of Earths cycles.

The cycles operate in very much the same way. Water transfers from one state to another, from an

ocean to clouds to rain to streams to rivers to oceans. All matter is neither created nor destroyed it just

shifts from one state to another.

Application in all of Earths Cycles

Carbon Emissions are expressed in terms of Carbon Dioxide Equivalent or Global Warming Potential (GWP).

This is expressed as CO2-e. The reason for this is the other gases that are GHGs as

discussed earlier. Each of these gases harm the atmosphere in differing

ways and amounts. It makes it easier to express them in the lowest

common denominator that being Carbon Dioxide

Terminology

Greenhouse Gas FormulaCO2-e in KgsGlobal Warming Potential

Carbon dioxide CO2 1Methane CH4 25Nitrous oxide N2O 298Sulphur hexafluoride SF6 22,800Hydrofluorocarbon-23 CHF3 14,800Hydrofluorocarbon-32 CH2F2 675Perfluoromethane CF4 7,390Perfluoroethane C2F6 12,200Perfluoropropane C3F8 8,830Perfluorobutane C4F10 8,860Perfluorocyclobutane c-C4F8 10,300Perfluoropentane C5F12 13,300Perfluorohexane C6F14 9,300

The GHGs Equivalencies

Carbon Emissions and Carbon Uptake since 1800 (Industrial Revolution)

Land Use Change

Deforestation;140 Gt CO2-e

Fossil Fuel Emissions

265 Gt CO2-eCAR

BON

EM

ISSI

ON

S

Oceans115 Gt CO2-e

Terrestrial/Tree and Plants

110 Gt CO2-e

Atmosphere180 Gt CO2-e

CAR

BON

EM

ISSI

ON

UPT

AKE

How does all this relate to Global Warming?

The burning of fossil fuels has increased exponentially since the Industrial Revolution 1800s. The natural uptake of GHGs has not and will not be able

to keep up with growth This has been the uptake of CO2 in Gt The 180 Gt yet to be abated is the problem We have produced more GHGs the we have been

able to abate

The normal processes in the Earths Cycle can no longer abate GHGs at the rate in which they are being produced.

The cycles are choked. The result Global Warming or Climate Change.

Simply Put

The following slides depict the potential consequence to some of Earths processes if we carry on with the amount of environmental degradation currently occurring in relation to climate change.

Projections

Temperature The basic projection is that the global surface air

temperature is going to increase with all scenarios. Even if the concentrations of all GHGs were kept constant at year 2000 levels, a further warming of about 0.1C per decade would be expected. If emissions are kept within the range of the IPCC scenarios about twice as much warming (0.2C per decade) can be expected.

Global Projections (1)

Global Precipitation For a future warmer climate, the current generation

of models indicate that precipitation will generally increase in tropical regions (such as the monsoon regimes) and over the tropical Pacific in particular. There is projected to be general decreases in the subtropics, and increases at high latitudes. Globally averaged mean water vapour, evaporation and precipitation are projected to increase.

Global Projections (2)

Precipitation Extremes and Droughts The Intensity of precipitation events is projected to

increase, particularly in tropical and high latitude areas that are due to experience increases in mean precipitation. Even in areas where mean precipitation decreases (most subtropical and mid-latitude regions), precipitation intensity is projected to increase meaning that there would be longer periods between rainfall events. There is a tendency for drying of the mid-continental areas during summer, indicating a greater risk of droughts in those regions.

Global Projections (3)

Snow and Ice As the climate warms, snow cover and sea ice

extent will decrease; glaciers and ice caps lose mass owing to a dominance of summer melting over winter precipitation increases. There is a projected reduction of sea ice in the 21st century in both the Arctic and Antarctic (see image below). Some models project summer sea ice cover to disappear entirely in the Arctic in the latter part of the 21st century. Widespread increases in thaw depth over much of the permafrost regions are projected to occur in response to warming.

Global Projection (4)

Tropical Cyclones (Hurricanes and Typhoons) Results from some global models, project a likely

increase in the intensity of tropical cyclones, but not in the number of them each year. Projections involving tropical cyclones are still rather uncertain.

Global Projections (5)

Ocean Circulation The overturning circulation of the Atlantic Ocean will

very likely slow down during the 21st century but is very unlikely to undergo a large abrupt transition during the 21st century. Partial deglaciation of polar ice sheets would imply major changes in coastlines and inundation of low-lying areas, with greatest effects in river deltas and low-lying islands.

Global Projections (6)

Particularly Vulnerable Areas The Arctic: because of the impacts of high rates of

projected warming on natural systems Africa: especially the sub-Saharan region, because of

projected climate-change impacts and low adaptive capacity

Small islands: due to high exposure of population and infrastructure to sea-level rise and increased storm surges

Asian mega deltas: due to large populations and high exposure to sea-level rise, storm surge and river flooding.

Global Projections (7)

As a result of global warming;The average global surface temperature is

risingSea temperatures are risingWeather patterns are changing Ecosystems are changing unpredictably

If not halted will it ultimately lead to the end of human kind?

Result

Result:Global surface temperature rise Globally the 10 warmest years on record have all occurred since 1990.Sea-level rise 20th century the sea-level has risen 10 20 cm. This is mainly due to thermal expansion, as the sea gets hotter, the water expands, causing it to rise. Projection state that from 1990 to 2100 seas could rise anywhere fro 10cm to 90 cm. As a consequence low-lying states, such as in the pacific islands stand a risk of being covered by sea water.Altered weather activity increased heat waves, fewer cold and frosts can extend the life of disease, higher rainfall, longer drought.

An Inconvenient Truth Al Gore

The Economics of Climate Change The Stern Review

The Weather Makers Tim Flannery

Further Reading (not compulsory)

END

Module 1 Climate Change ScienceTopicsWeather and ClimateWeather and ClimateClimate Change ScienceClimate Change ScienceConcentrations of common GHGsThe Greenhouse EffectScienceDivided OpinionsThe Precautionary PrincipleThe Precautionary PrincipleIPCC StatementScientific EvidenceHuman ActivityAn Inconvenient TruthWorld TemperaturesGHG ConcentrationsThe Climate SystemGlobal Energy BalanceThe Water CycleThe Carbon CycleThe Global CyclesThe Laws of ThermodynamicsDefined - The First LawThe First Law (Simplified)Defined - The Second LawThe Second Law (Simple)Application in all of Earths CyclesTerminologyThe GHGs EquivalenciesCarbon Emissions and Carbon Uptake since 1800 (Industrial Revolution)How does all this relate to Global Warming?Simply PutProjectionsGlobal Projections (1)Global Projections (2)Global Projections (3)Global Projection (4)Global Projections (5)Global Projections (6)Global Projections (7)ResultFurther Reading (not compulsory) 45