Tuesday, 31 May 2016

Climate Change - Animals are moving

Animals are reacting to climate change very quickly.

Some move to higher places, others move north or south.

Dragonflies love warmer temperatures.

UK dragonflies have mainly stayed in the south of the country, until recently.



Ruddy Darter (Sympetrum sanguineum)
That is over 2km per year..... nearly 6 metres per day.

For example, the ruddy darter (Sympetrum sanguineum) and the hairy dragonfly, (Brachytron pratense), have moved into north-west England. 

This is evidence that the UK’s climate is growing warmer.

"So much has happened to dragonflies in Britain since the 1990s that there is a most compelling case for the Government to adopt them as indicators of climate change", said Steve Brooks.
Mr Stephen Brooks

Scientists from the University of York  found that, on average, living things have "moved uphill" at 12.2 metres per decade.
  They are moving away from the equator at 17.6 kilometres per decade.
“These changes are equivalent to animals and plants shifting away from the Equator at around 20 cm per hour, for every hour of the day, for every day of the year. 
This has been going on for the last 40 years and is set to continue for at least the rest of this century.”
Dr I-Ching Chen said: 


“We have for the first time shown that the amount by which the distributions of species have changed is correlated with the amount the climate has changed in that region.”

I-Ching Chen and her colleagues discovered that moths had on average moved 67 metres uphill on Mount Kinabalu in Borneo.

Comma butterfly. Photo: Butterfly Conservation & Jim Asher
The Comma butterfly has moved 220 kilometres northwards from central     England to Edinburgh, in only two decades.

Monday, 30 May 2016

Climate Change - Where does the heat go?



As global warming continues, heat goes into all parts of the Earth's systems.

The Earth is gaining more heat than it loses, and most of that heat is going into the oceans.

More heat is going into the upper parts of the oceans.

The water in the oceans is expanding, which is one reason sea level is rising.



The deepest oceans are still cold.

Some of the heat is involved in melting ice, including Arctic sea ice.



The recent reduction in Arctic sea ice is very dramatic.

The ice sheets of Greenland and Antarctica are also melting.

Sunday, 29 May 2016

Climate Change - Hotter or colder?

The energy that affects the climate on the Earth originates from the Sun.
The energy emitted by the Sun passes through space, until it hits the Earth’s atmosphere.
Only about 40% of the solar energy hitting the top of the atmosphere passes through to the Earth’s surface.
The rest is reflected, or absorbed by the atmosphere. 

Here are some of the many factors that can cause the Earth's climate to get hotter or colder.  

These factors are sometimes referred to as 'forcings'.

Strength of the sun

The energy output of the sun is not constant, it varies over time.
Recently it has been reducing slightly.

The next two factors are astronomical cycles.

Changes in the Earth’s orbit

The Earth’s orbit around the Sun is an ellipse, not a circle, but the ellipse changes shape.
Sometimes it is almost circular - and the Earth stays approximately the same distance from the Sun as it orbits.
At other times the ellipse is more stretched, so that the Earth moves closer and further away from the sun as it orbits.
When the Earth is closer to the sun our climate is warmer.
Circular orbit

Elliptical orbit – when the Earth is closer to the Sun, its climate is warmer

Changes in the angle of the Earth’s axis of rotation



The Earth rotates around an axis (imagine a line that joins the north and south poles) but the Earth’s axis is not upright, it leans at an angle.
This angle changes with time.
Over about 41 000 years it moves from 22.1 degrees to 24.5 degrees and back again.
When the angle increases, the summers become warmer and the winters become colder.
Quantity of greenhouse gases in the atmosphere

These include carbon dioxide, methane and water vapour.
Of these, water vapour makes the greatest contribution to the greenhouse effect because there is more of it.
However, if one of those gases increases or decreases more than the others, it will be that gas that begins to affect the global temperature.

Carbon dioxide content of the oceans

The oceans contain more carbon dioxide (CO2) than the atmosphere and they can also absorb CO2 from the atmosphere.
When the CO2 is in the oceans it does not trap heat as it does when it is in the atmosphere.
Plate tectonics

Over time, plate tectonic processes cause continents to move to different positions on the globe.
For example, Britain was near to the equator 300 million years ago, and therefore was hotter than it is today.
The movement of the plates also causes volcanoes and mountains to form and these too can contribute to a change in climate.
Mountain ranges formed by plate tectonics. Large mountain chains can influence the circulation of air around the globe, and consequently influence the climate.  Warm air might be deflected somewhere cooler by the mountains.
Volcanoes formed by plate tectonics. Volcanoes affect the climate through the gases and dust particles thrown into the atmosphere during eruptions. The effect of the volcanic gases and dust may warm or cool the Earth's surface, depending on how sunlight interacts with the volcanic material.

Ocean currents

Ocean currents
Ocean currents carry heat around the Earth.
The direction of these currents can shift so that different areas become warmer and cooler.
Oceans store a large amount of heat, so that small changes in ocean currents can have a large effect on coastal and global climate.

Vegetation coverage on the land

On a global scale, patterns of vegetation and climate are closely correlated.
Vegetation absorbs carbon dioxide and this can buffer some of the effects of global warming.

Sum of the parts

Each of the above factors contribute to changes in the Earth’s climate, however the way they interact with each other makes it more complicated.
A change in any one of these can lead to additional and enhanced changes in the others.
For example, we understand that the oceans can take carbon dioxide out of the atmosphere:
When the quantity of CO2 in the atmosphere increases, the temperature of the Earth rises.
This in turn would contribute to a warming of the oceans. Warm oceans are less able to absorb CO2 than cold ones, so as the temperature rises, the oceans release more CO2 into the atmosphere, which in turn causes the temperature to rise again.

More on climate feedbacks here from the UK Met Office.

This post is largely based on material produced by the British Geological Survey.

Saturday, 28 May 2016

Climate Change - "The climate has always changed .......what is all the fuss about?"

The climate has changed before.


When people say "It's changed before without people, so people can't be involved this time" ....think of forest fires.



Fires happened throughout time, does that mean people can't start fires?

Ice ages, warm times ... the geological record in the rocks shows many events.

Even so, the current changes are very unusual.





Graph based on a paper published in 2013

Fig A2


The recent rise in temperature is very fast.


What other kinds of changes are happening?


Geologists have compared the past with the present.


This report -
Climate Change Evidence: The Geological Society of London


explains what they have discovered.

This is based on part of that report:

"Before the current warming trend began, temperatures were declining.

This cooling took Earth’s climate into the ‘Little Ice Age’ (1450 – 1850). 

Calculations indicate that this period of cool conditions should continue for about another 1,000 years. 

Nevertheless, after 1900 the overall decline in temperature sharply reversed." 

So the Earth should be cooling.

There's lots of evidence for human involvement in these changes.  
Atmospheric CO2 is now around 400 parts per million (ppm).
It last reached similar levels during the Pliocene, 5.3-2.6 million years ago.
Outcrop view

In the middle Pliocene, the concentration of carbon dioxide in the air ranged from about 380 to 450 parts per million. 

During this period, the area around the North Pole was much warmer and wetter than it is now.

Summer temperatures in the Arctic were around 15 degrees C, which is about 8 degrees C warmer than they are now.
Global average temperatures were 2-3°C warmer than today.

Sea level rose by up to 20 metres in places.

What are the risks?
This source gives examples relating mainly to the USA ..........

but applicable more widely too.

For more interesting information, see -

Fact Sheets produced by 

Friday, 27 May 2016

Climate Change - Greenland

The invention of the name Greenland may mark the start of the advertising industry.

The Saga of the Greenlanders tells how Erik the Red, the Icelandic Viking who wanted to get people to join his planned settlement, called it Greenland because a pleasant name would attract more settlers:

He called the land which he had found Greenland, because, quoth he, "people will be attracted thither, if the land has a good name." 

The ice sheet on Greenland covers most of this huge island.




Greenland is losing ice, and the mass of ice lost is measured by satellites called GRACE.

Embedded image permalink

A survey of Greenland's glaciers has shown they are speeding up.

The speed has increased by about 30% in 10 years.

A new NASA project called Oceans Melting Greenland (OMG) will observe changing water temperatures on the continental shelf surrounding Greenland, and how marine glaciers react to the presence of warm, salty Atlantic water.

Updates about Greenland's ice sheet are regularly posted by the National Snow and Ice Data Center.

Thursday, 26 May 2016

Climate Change - The last 22,000 years of global temperature change



This graph shows how temperatures have changed over the last 11,000 years, since the end of the last glacial stage.


The graph uses data from modern temperature records, plus information about the past from a research paper that combined data from over 70 different scientific studies.

The next graph adds data from even further back in time:


The green part covers the time as the last glacial stage was coming to an end, and the great ice sheets were melting.

The last glacial stage ended about 10,000 years ago. 

Then, for nearly 5,000 years, global temperature was surprisingly stable

In the next 5,000 years, up to about 1800, global temperature declined by about 0.7 deg.C.

There were some variations in that slow decline:


From 1800 until 2000, temperature rose by about 0.8 deg.C, according to the World Meteorological Organisation.




This chart shows annual average global temperatures from 1950-2015 using data from NASA's Goddard Institute for Space Studies (GISS)

Wednesday, 25 May 2016

Climate Change - El Nino

El Niño is an oscillation of the ocean-atmosphere system in the tropical Pacific, and has important consequences for weather around the world.

El Niño happens every three to seven years.

“El Niño” is Spanish for “The Little Boy”.

Peruvian fishermen named the event many years ago.

They noticed that every few years around Christmas, virtually no fish could be found in the unusually warm waters. 
El Niño is marked by unusually warm ocean temperatures in the Equatorial Pacific.

The opposite conditions are called La Nina (The Little Girl), characterized by unusually cold ocean temperatures in the Equatorial Pacific. 

El Nino clearly affects global temperatures.

One piece of evidence that world temperatures are rising is that every La Nina ‘year’ since 1998 was warmer than every El Nino ‘year’ before 1995:  


As the Earth warms, each El Nino 'rides' on a higher base-line global temperature:

The record-breaking temperatures of 2015 were partly boosted by an El Nino event ... but 2015 would have been the warmest year in the modern record even if there had been no El Nino.

Information about El Nino is provided in bulletins produced by the US National Weather Service and the Australian Bureau of Meteorology.

Tuesday, 24 May 2016

Climate Change - Doggerland

For many years, fishermen in the North Sea, between Britain and Denmark, have found fossil bones in their nets.



This fossil catch has yielded over 200 tons of fossil bones, and over 15,000 mammoth teeth.   

The bones include remains of mammoths, three different species of woolly rhinos, hippos, lionsbears, wild horsesbison, elk, reindeer, hyenas, wolves, and Sabre tooth cats of at least two species.   

They tell of a whole community of animals.

Beneath the North Sea lies a lost landscape.

This land was as big as modern Britain - hills and valleys, rivers and forests, marsh and moor. 

Sometimes warm and marshy, and at other times a frozen tundra.


This has been named "Doggerland".



"Doggerland" is a name given to a vast lowland plain, with the northern coastline stretching from Shetland to Jutland. 

The Thames flowed into the Rhine, which turned south, and made the English Channel its estuary. 

The highest point was a hilly region where the Dogger sand-banks are today.

Monday, 23 May 2016

Climate Change - The Experts

In the latest survey by Dr James Powell, 69,402 out of 69,406 climate change researchers accept human activity is causing global warming.

What do scientists who research climate change say?

Professor Tim Palmer FRS, Royal Society Research Professor in Climate Physics, University of Oxford:



“The threat of dangerous man-made changes to global climate is quite unequivocal. 
It follows that if we want to reduce this threat, we must cut our emissions of greenhouse gases."

Professor John Shepherd FRS, Ocean & Earth Science, University of Southampton:


“The evidence is very clear that the world is warming, and that human activities are the main cause. 
Natural changes and fluctuations do occur but they are relatively small."

Professor Joanna Haigh CBE FRS, Professor of Atmospheric Physics, Imperial College London:



The concentration of carbon dioxide in the Earth’s atmosphere now exceeds anything it has experienced in the past 3 million years and its continuing upward trend is almost certain to result in further global warming."

Professor Sir Brian Hoskins FRS, Director of the Grantham Institute for Climate Change at Imperial College London:




“The evidence of changes in many different aspects of the climate system, from the ice sheets to the deep ocean, shows that climate change is happening.   
To reduce the serious risks posed by increasing changes in the climate, we need to redouble our efforts globally to limit carbon dioxide and other greenhouse gas emissions.”

The Royal Society has also published a "Short Guide to Climate Change" 

Another organisation offering an important document is the Geological Society of London.

                                 
The Geological Society of London say -

This rate of increase of CO2 is unprecedented.....

even in comparison with the massive injection of carbon into the atmosphere 55 million years ago that led to the major PETM warming event....

and is likely to lead to a similar rise in both temperature and sea level. 

From.....

Climate Change: Evidence from the Geological Record

Another expert who is good at explaining climate change is 



Sunday, 22 May 2016

Planet Earth - 1816 - The Year Without a Summer

Climate reacts to sudden shocks.

The weather in 1816 was unprecedented. 

Spring arrived but then everything seemed to turn backward, as cold temperatures returned. 

The sky seemed permanently overcast. 


The lack of sunlight became so severe that farmers lost their crops.

Food shortages were reported in Ireland, France, England, and the United States.

It was over 100 years before anyone understood the reason for this weather disaster.

The eruption of an enormous volcano on a remote island in the Indian Ocean a year earlier had thrown enormous amounts of volcanic ash into the upper atmosphere.

The dust from Mount Tambora, which had erupted in early April 1815, had shrouded the globe. 

With sunlight blocked, 1816 did not have a normal summer.

In Switzerland, the dismal summer of 1816 led to the writing of a famous story. 

A group of writers, including Lord Byron, Percy Bysshe Shelley, and his future wife Mary, challenged each other to write dark tales inspired by the gloomy and chilly weather.

During the miserable weather Mary Shelley wrote her classic novel Frankenstein.

This event was not unique.

A new study has found that 15 of the 16 coldest summers recorded between 500 B.C. and A.D. 1,000 followed large volcanic eruptions.

Saturday, 21 May 2016

Climate Change - Glacial archaeology

Norway is dotted with small glaciers, and 'permanent' snow patches .

Around 7,000 years ago (5000 BC) the Earth was enjoying a warm climate:



Then it cooled, allowing those icy areas to form.



Now those glaciers and patches of perennial ice in the high mountains of Southern Norway have started to melt again, as the Earth is warming. 

They contain all sorts of archaeological treasures.

Anything from ancient shoes to 5000-year-old arrowheads. 

As a result a new kind of archaeology has begun - Glacial archaeology.

6_norways-oldest-shoe

In 2006, an amateur archaeologist came across an amazingly well-preserved ancient leather shoe in the Lendbreen ice patch in Norway. 

When the shoe was examined and tested, archaeologists discovered the shoe was over 3,000 years old, and dated from the Bronze Age.

"Actually we should be slowly approaching a new ice age. 
But in the past 20 years we have witnessed artefacts turning up in summer from increasingly deeper layers of the glaciers." says Lars Pilø.
Lars does fieldwork in glaciers and ice patches, finding things discarded or lost by people long ago.

Glacial archaeology is becoming a fascinating new field of research.

Friday, 20 May 2016

Climate Change - Ocean acidification - what does it mean?

The phrase 'ocean acidification' means that the pH of seawater is falling.

The pH scale is used by scientists to describe strength of acids and alkalis. 

Sea water normally had a pH around 8.2 

It has now reduced to 8.1, and will continue to reduce, as more CO2 is added to the air by human activities.



Some of the extra COin the air dissolves in the sea, and this affects sealife.

Here is what one expert scientist has said about this -

"A drop of 0.1-unit pH is equivalent to about a 26% increase in the ocean hydrogen ion concentration.
"pH is likely to drop by 0.3-0.4 units by the end of the 21st century. 
"This will increase ocean hydrogen ion concentration (or acidity) by 100-150% above what it was in pre-industrial times."



Humanity's greenhouse gas emissions may be acidifying the oceans at a faster rate than at any time in the last 300 million years. 

With ocean acidification, corals cannot absorb the calcium carbonate they need to maintain their skeletons.

The stony skeletons that support corals and reefs will dissolve.


Picture A shows healthy coral.     Picture B shows dead and dying coral.
A healthy coral reef with living Acropora palmata and good water quality and a degraded coral reef with dead A. palmata and poor water quality.  

The U.S. Geological Survey (USGS) is conducting research on ocean acidification in the Arctic, Gulf of Mexico and Florida estuaries, and the Caribbean and Pacific.