Climatic effects on species- range and behaviour

Every species has particular optimum environmental conditions for survival. As climate alters they either:

• Migrate (invading a new area and mixing with formerly non-overlapping species. This can lead to knock-on effects throughout the ecosystem and can cause extinctions)
• Adapt their behaviour

Changes in species distribution- Spatial

• Killer whales with tall dorsal fin are moving into previosuly ice-bound Artic waters and siplacing bowhead whales
• Adelie penguin rookeries being replaced by Gentoo penguins on the Antartic peninsulars
• 60 species of butterfly have moved north in Europe, e.g. Polygonia comma butterfly is spreading north in UK at a rate of 10km a year
• Concern that pests of species are linked with diseases could spread more widely, e.g. Anopheles mosquito which carries Malaria

Changes in species physiology and behaviour- Tempral

• Shifts in Phenology (timing of biological activities that take place seasonally)- migrant birds, butterflies and plants are arriving earlier.

Changes in physiology and behaviour- Tempral

• Polar bears find it difficult to hunt seals during the summer ice-free periods. As the Artic warms the Polar bears have become underweight as they have a shorter amount of time toi hunt for food.

What are the issues resulting from Climate Change??

Changing climates, shifting climatic belts and the effects on biomes

1. A change in that climate will therefore change that ecosystem
2. 'Macro-scale' effects

• Climatic ranges are moving North 50km-80km every 10 years
• Shifting climatic belts polewards (also known as the migration of climatic belts)

3. Shifting Climatic belts leads to changing biomes

• By 2100, 40% of biomes will have switched to a different state

Temperate Grasslands-Mid Latitudes

• Temperate Grasslands on the steppes of North Asia and North American prairies will have drier summers and colder winters.
• These regions are the 'bread baskets' of the world-the principle grain-growing areas
• Climate change will reduce grain yields,food production and income for farmers
• This could lead to food shortages

Tundra and Northern tree line-High Latitudes

• Melting permafrost leads to: Loss of habitats-wildlife adapted to survive tundra conditions, subsidence-damaging settlements,transport and oil pipelines in Alaska and Siberia, increased sediment in rivers- increased erosion of the banks affect wildlife including the salmon that migrate upstream to spawn.
• Release of methane and carbon dioxide previously locked up in frozen ground (positive feedback loop accelerating global warming)

Rainforest, Savanna and Desert-Low Latitudes

• Tropical biomes seem to be tied to specific climate tipping points (Gilf Kebir). When certain climatic thresholds are crossed (especially precipitation level/distribution), the one ecosystem can suddenly switch to another
• Could be beneficial to some areas-e.g. Sahel where movement of the rain belt Northwards could halt desertification

Increasing levels of Extreme Weather

Extreme weather events classified as hydro-meteorological hazards by the Emergency Events Database.

Increase in reported extreme weather

• Frequency (how often)
• Magnitude (size)
• Impact (amount of damage)

Flood events

• Coastal river and flash flooding
• 10% of land surface is very flood prone
• Flood prone land contains 40% of the world's people.
• Areas include Midwest USA, coastal South America, Bangladesh and Northern England.

Storms

• Mainly tropical cyclones (hurricanes, typhoons)
• Can include tornadoes and temperate storms
• Concentrated in tropical belts, especially coastal areas covering 7% of the world's area but 24% of the world's population.

Droughts

• A drought is when there is less than 50% median rainfall over 3 or more months
• Often includes extreme,heat,wildfires and the secondary hazard of famine
• Affects 40% of the world's land surface containing 70% of the population and 70% of agricultural production

Slides

• Can be a secondary hazard resulting from extreme weather (e.g. heavy rain or snowfall. Includes avalanches)
• Affects 5% of the world's population

What are the reasons for the increasing level of extreme weather?

• More reporting because of improved communication
• Different methods of recording events
• Population growth leads top densely populated hazard prone areas
• Deforestation and land degradation, increasing magnitude of floods and droughts
• Climate Change has an impact on extreme weather but there are other contributing factors

Risky Sea Levels

The IPCC (Intergovernment Panel for Climate Change) predicted the sea level rise for 2080

• Low Emission Scenario-9.48cm
• High Emission Scenario-16.69cm

Whatever happens sea levels will rise.

Causes (Key factors associated with climate change):

• Warming ocean-water expands and more precipitation (Thermal expansion).
• Exchange of water stored on land as glaciers and ice caps with ocean water.
• Sea levels could rise up by 7 metres if Greenland melted entirely.
• Glacial retreat

Impacts:

• The weight of ice cover caused crust to sink-creating a see-saw effect
• Out of the 15 largest cities-13 of them will be affected by sea level rise as they are on the coast
• Sea level rise in the UK will affect the South and East of the UK which would cause flooding and coastal erosion
• Small islands in the Pacific and Indian Oceans will be affected the most

Geometry of the Oceans

The oceans influence climate over long and short time scales. The oceans and the atmosphere are tightly linked together to form the most dynamic component of the climate system. The oceans play a critical role in storing heat and carbon. The ocean's waters are being constantly moved by powerful currents which are mainly wind-driven. These currents influence the climate by transporting heat. Currents involved in 'deep-water formation' are particularly important for climate. Apparently a small change in just one aspect of the ocean's behaviour can produce major climate variations over large areas of the Earth.

Thermohaline Circulation

What is it?

Thermohaline circulation is a part of the large-scale ocean circulation that is driven by global density gradients created by heat and fresh water fluxes. It is also known as the ocean conveyor belt, great ocean conveyor or the global conveyor belt. It supplies heat to the polar regions and regulates the amount of ice in those regions.

In 2005, the net flow of the Northern Gulf Stream had decreased by 30% since 1957.

Thermo-Heat
Haline-Salt Content

ENSO

El Nino

• Short-term climatic disruption
• Occurs at intervals between 2-7 years
• Typically lasts between 12-18 months
• Also known as ENSO warm event
• Arrival of warm surface water in the Eastern equatorial Pacific (off Peru and Equador)
• Often occurs at Christmas, giving name to event 'Christ Child'
• The current that brings cold water to the west coast of South America is called the Humbololts Current

Normal Air Circulation in the Central Pacific is called the Walker Loop

Process of a normal year of the El Nino Southern Oscillation

1. South East Trade Winds

• Part of global atmospheric circulation pattern.
• Not below -30 degrees and not above the equator.

2.Warm water builds up in Western Pacific

• Sea level is 50cm higher here.

3.Warm water heats the air causing convection currents and low pressure leading to high precipitation.

4.Tropical rainforest biome forms because of warm wet conditions

5.Cooler air sinks leading to dry conditions on the west coast of South America once the air has returned east.

Process of an El Nino year of the El Nino Southern Oscillation

1.South East trade winds drop

2.Warm water moves back towards the East

• Sea level on the Peruvian coast rises by 30cm

3.Air circulation reversed. Sinking air brings drought conditions to Western Pacific regions. Rising air causes convectional rainfall which can lead to floods in coastal areas of South America, which devastates the fishing industry.

Volcanoes lead to cooling???

Many examples show that volcanic eruptions lead to the cooling of the climate. Laki in Iceland erupted in 1783 and that winter was the coldest ever recorded in the North East of USA. Tambora in Indonesia erupted in 1815. An extremely cold spring and summer followed this eruption in 1816. Snowfalls and frosts occurred in June, July and August in Europe and North America which led to the failure of crops and therefore famine. Also, Atlantic shipping lanes were blocked by ice and alpine glaciers advanced significantly. Krakatay which is also in Indonesia erupted in 1883. This eruption was the second biggest eruption that has happened and caused the island to split. Pinatubo in the Philippines erupted in 1991 and the aerosol plume traveled around thew world in days. Global air temperatures dropped by 1 degree Celsius. This eruption demonstrated the link between sulphur (not ash) and cooling.

How does sulphur in the atmosphere lead to cooling?

https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwigscrXq_DKAhXMFZoKHa4qB3gQjB0IBg&url=http%3A%2F%2Fplaza.ufl.edu%2Fairwess%2F&psig=AFQjCNEO8Dhw9I54bat6hpkY9_zSfUS8UQ&ust=1455301653689132
The volcanic eruption emits huge amounts of Sulphur dioxide into the atmosphere. This combines with water to make fine particles (aerosols) of sulphuric acid. The aerosols reflects the in coming solar radiation which means that less radiation reaches the Earth's surface and therefore leads to cooling. The extra carbon dioxide from volcanic eruptions does not have a significant impact compare to anthropogenic annual emissions.

The Evidence

Evidence from the Cyrosphere

The Artic has reduced in ice by 30% and the thickness has reduced by a half since 1980.

Greenland's land ice is moving down to the sea twice as fast as previously which has a significant effect on the sea level.

Glaciers grow and shrink in response to climate for example Solheim Glacier in Iceland.

Ice core analysis

Where they are analyzing the ice is in Greenland and Antarctica. They measure by drilling down into the ice which is thousand of years old. The layers are the winter snowfall compressed into ice which can be analysed for temperature and the trapped gases (oxygen isotopes) can be analysed for carbon dioxide. The oldest ice core is called Vostok which is 400,000 years old.

Cross dating in trees

Climate conditions influence tree growth, patterns in tree-ring widths and density.In temperate regions where there is a distinct growing season, trees generally produce one ring a year, recording the climate conditions each year. Trees can grow to be hundreds to thousands of years old and can contain annual records of climate for centuries to millennia.

Milankovitch Cycles

The theory was developed by Serbian, Milutin Milankovitch in 1924 and they are changes in the Earth's orbit and axis tilt which lead to a change in climate and therefore biome. There are variations in the amount and distribution of solar radiation received by the Earth which results in long term changes in the surface temperature of the Earth.

Impact of orbital changes on solar radiation is relatively small and would only lead to approximately 0.5 Celsius in the global temperature. Milankovitch cycles act as the trigger to major global climate change. Climate feedback mechanisms are needed to sustain change.

Orbital Eccentricity (changes in orbit)

https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwim4N6qnfDKAhWH0xQKHS7XBH8QjB0IBg&url=http%3A%2F%2Fwww.ces.fau.edu%2Fnasa%2Fmodule-3%2Ftemperature-trend-changes%2Fcauses-glaciation.php&psig=AFQjCNEUkvjp58-LZbEleaceSiFAMKQkKw&ust=1455297905173325

Obliquity (changes in tilt)

https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjHr_ihnvDKAhUC6xQKHY_uB5UQjB0IBg&url=http%3A%2F%2Fpics-about-space.com%2Fobliquity-of-earth-orbit%3Fp%3D1&bvm=bv.113943164,d.d24&psig=AFQjCNEf1AYvpKbWPE-poryDipbWlJCzsA&ust=1455298150388111

Precession (Axial wobble)

This happens every 22,000 years.

https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjKq8LgnfDKAhXDbxQKHebfC_wQjB0IBg&url=http%3A%2F%2Fwww.mhhe.com%2Fphyssci%2Fastronomy%2Ffix%2Fstudent%2Fchapter3%2F03f15.html&bvm=bv.113943164,d.d24&psig=AFQjCNF368IerdHMOUv52fgfdKrqhMcXVQ&ust=1455298012745229

Types of feedback

Snowball Earth and Chemical Weathering

The Earth 4 billion years ago used to be warmer than it is today. There was a thicker blanket around the Earth and the sun was 25% fainter than it is today which kept the sun warm. But where did the thick blanket or carbon dioxide go?

Chemical Weathering

This is where carbon dioxide and rainwater forms a weak acid called carbonic acid which dissolves silicate rocks. The carbon from the rocks in the form of bicarbonate ions washes into the ocean, where it is used by many organisms to form their shells and are deposited on the ocean bed to form carbonate rocks. This was where the carbon was kept and explains how our climate is self regulated. Even though the sun is getting brighter, we haven't seen a proportional increase in the Earth's temperature. This is an example of negative feedback. As the Earth's temperature began to increase, then so did the rate of chemical weathering.

Snowball Earth

2.2 billion and 700 million years ago our planet became a giant snowball. The growth of continents and the removal of carbon dioxide by weathering cools the planet, then ice cover increases which also means that reflectivity increases. This reflectivity reduces the absorption of sunlight by the Earth's surface and so increases the temperature further etc etc.... This produces positive feedback which is usually restricted. It amplifies the spread of ice cover away from the poles. If it reaches the tropics which is a tipping point where the process of amplification runs away and we get a Snowball Earth with the ice closing up the equator.

The Weathering process is stopped by the cover of ice,but volcanoes are still pumping carbon dioxide into the atmosphere which has no where to go as the carbon sink has been switched off. This creates a blanket warming the ice around the equator which causes the rest of the ice to melt. This kick starts the Weathering process once again and returning the carbon dioxide to the Earth's crust.

Climate System

The Climate System

It is a system that has five key components, the atmosphere, the hydrosphere (this includes the oceans, fresh water, rivers, lakes, and groundwater), the biosphere (living things and soils), the cryosphere (ice sheets, sea ice, and mountain glaciers) and finally the lithosphere (the surface of the Earth's crust).

http://worldoceanreview.com/en/wor-1/climate-system/earth-climate-system/ 
The Water Cycle


Solar radiation causes water to evaporate from the surfaces of the hydrosphere, and also from the biosphere. The water vapour condenses in the atmosphere to form clouds, and water returns to the surface through precipitation. On reaching the surface, water returns to the hydrosphere, it can enter the cryosphere. Sunlight on the cryosphere can melt snow and ice or transform it directly into vapour in a process called 'sublimation' from ice sheets, show fields, and glaciers.

http://www.srh.noaa.gov/jetstream/atmos/hydro.htm 

Human feedback


There are three main feedbacks which are:

• Water vapour feedback 
• Ice Albedo feedback 
• Radiation feedback 

Water vapour feedback


Evaporation occurs when solar radiation heats the surface of bodies of water. The evaporated water is transformed from the liquid to the gas phase and stored in the atmosphere. The molecules of water vapour in the atmosphere absorb heat radiation coming from the Earth below, causing them to vibrate. Then they re-emit heat radiation, some of which comes back down to the surface, resulting in further warming. This increased warming in turn increases the amount of evaporation in an amplifying process, which we call a positive feedback. If we increase temperature, then evaporation increases.

http://www.wsj.com/articles/SB10001424052748704194504575031404275769886
The Ice Albedo feedback


If we take an area of ocean that is mostly covered by sea ice, say in the Arctic, much of the solar radiation that is reaching the surface will be reflected back into the atmosphere by the highly reflective ice. The ocean's surface, on the other hand, will reflect some solar radiation, but it tends to absorb more than it reflects. So if we warm the system up and this melts some sea ice, we'll still have some reflection from the remaining sea ice. But where open water is exposed we'll get much more absorption of incoming sunlight as heat going into the ocean.

http://ossfoundation.us/projects/environment/global-warming/myths/images/arctic/icealbedo.jpg/view
Radiation feedback


All objects give off radiation, but the warmer a body is the more radiation it gives off. And when a warm body gives off more heat radiation, that cools it down. This phenomenon is known as the Stefan Boltzmann effect or the Planck feedback. The Climate system is a system that self-regulates thanks to a mixture of positive and negative feedback. They link together the different components of the climate system.

Weather and Climate

Weather is the state of the atmosphere at a particular point at a specific time which can be described in terms of:

• Temperature
• Precipitation
• Wind speed and direction
• Cloud type and cover
• Humidity
• Visibility

Climate are the average atmospheric conditions of an area measured over a substantial period of time (usually 30 years). This is mainly based on temperature and precipitation.

Koppen classification

There are six broad categories which are:

• Tropical moist climates- all months have an average temperatures above 18 Celsius.
• Dry climates- with deficient precipitation during most of the year.
• Moist mid-latitude- Climates with mild winters (Temperate).
• Moist mid-latitude- Climates with cold winters (continental).
• Polar climates- extremely cold winters and summers.
• Mountain  climates- This category was added later.

http://www.blueplanetbiomes.org/world_biomes.htm

Scientists have to look at how the atmosphere interacts with the oceans, ice sheets, land masses and vegetation. These different interactions create a climate system and these interactions as well as the composition of the atmosphere itself make a very complex system. The sun also drives our climate. Sunlight provides energy which heats the Earth.Without the Earth's atmosphere and certain gases our climate would be very different to what it is now. The atmosphere stops the heat from escaping into space. If it didn't do this our planet would be a very cold place indeed. Certain gases allow the suns energy through but stop it from escaping back into space, acting like a green house. To learn more about the greenhouse effect please read another blog post of mine called 'Blanket Earth'.

Blanket Earth

The main idea for our climate change is the 'Enhanced Greenhouse effect'.

The Greenhouse effect

There is a naturally occurring layer of greenhouse gases in our atmosphere that have made the Earth warm enough for life to flourish.

http://www.livescience.com/37743-greenhouse-effect.html

As the diagram above already explain, people can effect the greenhouse effect. Humans can produce more greenhouse gases which means less infrared radiation escapes to space and therefore warming the Earth too much. Hence the 'Enhanced Greenhouse Effect'. As the Earth warms, the ice caps will melt which will create a rise in sea levels and therefore more flooding.

Greenhouse gases

The natural gases that contribute are: Water vapour, Methane, Carbon dioxide and Nitrous oxide and the only gas that is artificial that contributes are F-gases ( CFCs).
Water vapour is the most abudant greenhouse gas and also it acts as a feedback to the climate. As Water vapour in

creases the Earth warms, as does precipitation creating more Water vapour.

Carbon dioxide is the most important human greenhouse gas which is produced by burning fossil fuels (there has been a rise in CO2 levels since pre-industrial times) and deforestation.

Methane is the second most important greenhouse gas as it is produced by farming (especially cattle and rice), fossil fuel extraction and the decaying of organic waste.

Nitrous oxide is also produced from farming (fertilisers and livestock waste) and industrial processes which also produces F-gases along with refrigeration.

Solar Variability

Its reasonable to assume that the changes in the source's output would be the cause of our climate to change but the amount of energy that the Earth receives from the Sun is relatively stable, however variations occur such as the sunspot cycle ( approximately every 11 years) which result in increased magnetic activity which can be released as solar flares.

A case study that shows a decrease in solar activity is thought to have triggered the Little Ice Age between approximately 1650 and 1850, when Greenland was largely cut off by ice from 1410 to the 1720s and glaciers advanced in the Alps.

If you would like to find out more you can read this article (http://climate.nasa.gov/causes/) by NASA which explains about the contributing gases, the effect that burning fossil fuels has and solar variability.