Tag Archives: A-Z of Global Warming

A-Z of Global Warming: 2012 Edition. C – Carbon Dioxide.

22 Dec

C – CARBON DIOXIDE

 

Okay, so we are now well into our alphabetic A–Z journey throughglobal warming. C for Carbon Dioxide is one of the main playersin the global-warming problem. Carbon dioxide, chemical symbolCO2, is a chemical compound composed of one carbon and twooxygen atoms.1

CO2 is present in the Earth’s atmosphere at a low concentration, about 0.038 per cent by volume, and is one of many gases that make up Earth’s atmosphere (see Chapter G). CO2 is measured in parts per million by volume of air (ppmv). Atmospheric CO2 derives from many natural sources, including volcanic eruptions, the combustion of organic matter, the respiration of living aerobic organisms, and unfortunately from manmade (anthropogenic) sources, which we all know from the news is being linked to global warming and climate change.

Since the Industrial Revolution, particularly the mid – nineteenth century, the burning of fossil fuels for energy to provide electricity, power factories and homes, and for all our transport needs, has released massive amounts of CO2 into the atmosphere. Not only the burning of fossil fuels, but changes in the use of the land for agriculture and deforestation (looked at in the next chapter), have further added to global manmade CO2 levels.

According to the WWF some twenty-nine gigatons, which is 29,000,000,000 metric tons of CO2, were, in 2004 alone, added to the atmosphere from burning coal, oil and gas. If we go back 250 years or so, to pre-industrial times, usually taken to be approximately 1750, CO2 levels in the atmosphere stood at about 280 parts per million by volume (ppmv). However, levels of the gas have been increasing steadily ever since.

How do we know this?

 

Well, pioneering scientist Charles Keeling (1928–2005) started taking atmospheric CO2 measurements in 1958 from Mauna Loa volcano in Hawaii. Those measurements have been recorded and are now known as the Keeling curve. Charles Keeling was the professor of oceanography at the Scripps Institute of Oceanography (SIO), in San Diego, USA. He followed the work of another eminent scientist and director of the SIO, Roger Revelle. Dr Revelle was instrumental in creating the Geophysical Year in 1958, and SIO’s first programme looking at atmospheric CO2 back in 1956.

Monthly CO2 measurements were collected from a height of 3,397 metres (11,140 feet) at the Mauna Loa Observatory situated on the slopes of Earth’s largest volcano, Mauna Loa, which was

chosen for its remoteness from populations and vegetation, so as not to skew the readings.

Measurements have been taken over a fifty-nine-year period, between 1958 and present, and show an increase in CO2 levels of 70 ppmv from about 315 ppmv to approximately their current level of 385 ppmv. The effects of CO2 in the atmosphere can even be measured on a cyclical basis, and this can be seen in the saw-toothed Keeling graph. Because there is a greater land area, and thus far more plant life in the northern hemisphere (as mentioned in Chapter A) compared to the southern hemisphere, there is an annual fluctuation of about five ppmv peaking in May and reaching a minimum in October. This corresponds to the northern hemisphere growing season. The amount of CO2 in the atmosphere drops towards spring, when uptake by the plants and trees by photosynthesis is greatest. The opposite occurs in winter when the plants die off and CO2 levels rise again.2

Continuous readings in this way have been taken only since 1958. However, scientists have discovered that prior to the industrial era, circa 1750, CO2 levels stood at about 280 ppmv, and this data has been revealed from air trapped in ice core records, taken from both the Antarctic and Arctic.3 Perhaps most startling is the fact that CO2 levels are now about eighty-five ppmv higher than at any time during the last 650,000 years. Records from ice-core records go back that far and have shown atmospheric CO2 levels to range from 180-300 ppmv during that period. The level of CO2 in our atmosphere now stands at 385 ppmv, and is increasing steadily.4 , 5 , 6

The Keeling curve has become one of the most recognisable images in modern science, as it shows with no uncertainty the effects of humankind’s fossil-fuel pollution of Earth’s atmosphere.

CO2 levels have increased by thirty-seven per cent since preindustrial times and have been increasing by an average of almost 1.4 ppmv a year since measurements began in 1958 – although some months the figure has been higher, sometimes lower. In the last ten years, the average increase appears to be about 1.9 ppmv each year, which indicates the rate of increase is increasing. This is looked at further in Chapter I.

Where does all the CO2 go?

 

It is estimated that about fifty per cent is absorbed by the oceans and land (soil, plants, trees etc.) in equal amounts, and fifty per cent remains in the atmosphere. The oceans absorb vast amounts of CO2 and act as a major sink/store for the gas, just as do the forests of the Amazon. However, the oceans take a relatively long time to absorb the CO2 that is pumped into the atmosphere, and

therefore the effects of current CO2 levels may not be reflected by the oceans for some time to come. The oceans can sustain many times more CO2 than the atmosphere can. According to NOAA the oceans have taken up about 118,000,000,000 metric tons of CO2 from human sources (anthropogenic CO2) between 1800 and 1994. This equates to about forty-eight per cent of all manmade CO2, which would be enough to push atmospheric CO2 up by an additional fifty-five ppm.

Why is carbon dioxide such a problem?

 

Basically global-warming theory predicts that increasing amounts of CO2 (and other gases) in the atmosphere tend to enhance the greenhouse effect and thus contribute to global warming. Despite

CO2 being present in the atmosphere in small concentration, natural CO2 levels are a very important component of Earth’s atmosphere. As mentioned earlier, CO2 is one of Earth’s natural

greenhouse gases and it helps the Earth maintain its temperature by trapping some of the sun’s heat, which would otherwise escape back into space. If this did not happen the Earth would be some 30°C (54°F) cooler and have an average temperature of about -18°C (-0.4°F) – pretty chilly, unless of course you are a penguin!

CO2 is also essential for life on Earth. Photosynthesis, the process by which plants and trees absorb CO2 and produce oxygen, could not occur without it. In the distant past volcanoes were the main source of Earth’s CO2, and there are still lots of active volcanoes on Earth, such as Mount Etna and Stromboli in Italy, which have been erupting continuously for thousands of years. Erupting volcanoes are just part of Earth’s natural CO2 cycle, and the CO2 they emit will eventually be absorbed back into the oceans and the land.

CO2 is only one of the gases that make up the Earth’s atmosphere that are collectively referred to as greenhouse gases. As we shall see in later chapters, the higher the level of greenhouse gases of which manmade CO2 is a component, the higher the Earth’s temperature is likely to be. The effects of higher temperatures could be catastrophic, as we shall be reminded throughout this book.

We will now look at deforestation, which is a continuing problem, and which destroys the Earth’s rainforests ability to soak up CO2. The rainforests  destruction also adds to CO2 levels as dead and decaying trees release their stores of carbon back into the atmosphere that were taken out over many decades of growth.

CARBON DIOXIDE 2012 UPDATE.

 

So, what’s the position with CO2 levels now? Well, they have continued to increase and now stand at 393 ppm. Click on the following link to be taken to the  NOAA website which gives a graph taken from the Mauna Loa data. An increase of 10 ppm in the four years since this book was first written.

A record-setting 30.6 billion tons of carbon dioxide was added to the atmosphere in 2010. That’s a 45 per cent increase in the global annual release of carbon dioxide by humans since 1990, reports the International Energy Agency.  According to the Guardian report, Professor Lord Stern of the London School of Economics, the author of the influential Stern Report into the economics of climate change for the Treasury in 2006, warned that if the pattern continued, the results would be dire. “These figures indicate that [emissions] are now close to being back on a ‘business as usual’ path. According to the [Intergovernmental Panel on Climate Change’s] projections, such a path would mean around a 50% chance of a rise in global average temperature of more than 4C by 2100,” he said. “Such warming would disrupt the lives and livelihoods of hundreds of millions of people across the planet, leading to widespread mass migration and conflict. That is a risk any sane person would seek to drastically reduce.”

In 2011, reports Reuters, global CO2 emissions rose a further 3.2 per cent to 34.83 billion tons, with China making the largest contribution to the rise.

In 2012, CO2 emissions were again forecast to rise to 35.6 billion tonnes – ScienceDaily.

Many scientists have long suspected that rising levels of carbon dioxide and the global warming that ended the last Ice Age were somehow linked, but establishing a clear cause-and-effect relationship between CO2 and global warming from the geologic record has remained difficult.

A new study, funded by the National Science Foundation and published in the journal Nature, identifies this relationship and provides compelling evidence that rising CO2 caused much of the global warming.

Despite biofuels being developed for jet-engines, recent predictions for aircraft CO2 emissions show they will double or triple by 2050. Currently global aircraft emissions contribute around 2-3 per cent of carbon dioxide emissions. More worryingly, global emissions are set to increase by 43 per cent by 2035 as fossil fuels remain the number one energy source and coal becomes the number one fuel. Carbon capture and storage technology is unlikely to keep up with the pace of coal burning energy production.

The bad news is that CO2 levels are continuing to rise, forcing Earth’s temperature up as they do. Greenhouse gases, of which CO2 is just one, will be looked at further in chapter G.

Key points

 

➢ CO2 is just one of Earth’s greenhouse gases and makes up just 0.038 per cent by volume of atmospheric gas.

➢ Levels of CO2 have increased from 280 to 393 ppmv since circa 1750, an increase of thirty seven per cent, mainly as a result of burning fossil fuels.

➢ CO2 is a global-warming gas and current levels are higher than at any time in the last 650,000 years.

Professor Charles Keeling started taking measurements of CO2 from Mauna Loa Observatory in Hawaii, and they show an increase from 315 to 393 ppm since 1958.

1 Wikipedia (carbon dioxide).

2 NASA, http://www.visibleearth.nasa.gov, the Keeling curve.

3 Stern Review on The Economics of Climate Change, Part I.

4 Ibid.

5 Real Climate, http://www.realclimate.org.

6 Mongabay.

images (2)

The Sun: What’s The Fuss Over Solar Flares?

9 Mar

THE SUN

With the Sun and Solar Flares currently in the news, i thought i’d update my blog by adding chapter S from my book The A-Z of Global Warming, which discusses the Sun’s impact of global warming, and gives some facts and figures on Earth’s nearest star…

Bear in mind the book was written in 2008 – but mentions the increase in Solar activity now in the news…

The sun is a star, which is located at the centre of our solar system.
It is only one of about 100 billion stars in our own galaxy, the
Milky Way, which in turn is one galaxy of literally billions in the
universe, each containing billions and billions of stars.
Our sun has been in existence for about 4,600,000,000 years,
and it will provide life support for planet Earth for another 5–
6,000,000,000 years, until it transforms into a red giant gas star
and finally dies.
The energy from our sun, in the form of sunlight, supports
life on Earth and is responsible for the Earth’s weather and climate
systems. The sun cannot be ignored in the context of global warming.

Earth’s power supply

The surface of the sun has a temperature of about 5,500°C (9,932°F),
and it’s even hotter on the inside! As you might expect, being
the only source of heat in our solar system, its effects on Earth’s
climate and temperature will be significant.
The total amount of radiant energy emitted by the sun that
reaches Earth is termed the total solar irradiance or TSI, and it
is measured in watts per metre squared.
Energy from the sun is measured both at the top of the Earth’s
atmosphere, called the solar constant, and at the surface of the
Earth, insolation.

Has the sun caused or contributed to global warming?

This is the question many scientists are trying to answer. NASA
satellites have measured total solar irradiance since 1978. Six
overlapping satellites have monitored TSI since 1978, and the first
records came from the Nimbus 7 Earth radiation budget (ERB)
experiment from 1978–1993. NASA’s ACRIM 1 satellite, which
is an acronym for Active Cavity Radiometer Irradiance Monitors,
also studied the sun, from 1980–1989, and ACRIM 2 from 1991–
2001. Finally ACRIM 3 from 2000–2005.
These satellites produced a wealth of information about the
sun. Richard Wilson, a researcher affiliated with NASA’s Goddard
Institute for Space Studies and Columbia University Earth Institute
in New York, compiled TSI records over the twenty-four-year
observation period by piecing together the records.
The results showed a 0.05 per cent decade upward trend of
TSI measured in watts per metre squared between solar minimum
solar cycles, 1978 to the present (solar cycles twenty-one to twenty-three).

What are solar cycles?

The sun goes through cycles, called solar cycles, every eleven years.
During this period the sun goes through a period of increased
magnetic and sunspot activity, called the solar maximum, when
solar-energy output increases, followed by a quieter period, called
the solar minimum, and back again. During a solar cycle, the
number of sunspots also varies with solar minimum and solar
maximum, with peak sunspot activity occurring at the solar
maximum.

What are sunspots?

Sunspots are basically dark and relatively cooler regions of the

sun, caused by concentrated magnetic fields. Sunspots can cause

decreases in TSI by about 0.2 per cent during say a week-long
passage of a large sunspot group across the ‘Earth facing’ surface
of the sun. These changes are insignificant however to the sun’s
total output of energy, but still equivalent to all the energy
mankind produces and consumes in one year!
So, when the sun is at solar maximum, irradiance and magnetic
activity are at their highest, which is proportional to solar activity.
Sunspot numbers are representative of the general level of solar
activity.
At present the sun is just coming out of a quiet period, which
is solar minimum of solar cycle twenty-three. The last solar
maximum was in about the years 2000–2002 (cycle twenty-three).
NASA scientists have recently discovered a new technique,
‘helioseismology’, which works in a similar way to ultrasound,
but in the case of the sun, not part of the human body!
The sun’s magnetic fields, plasma flows and magnetic
signatures left by fading sunspots are looked at by NASA’s solar
and heliosphere observation satellite (SOHO). This has led the
NASA team to predict that the sun’s next solar cycle will begin
with an increase in solar activity in late 2007 or early 2008, and
this will be thirty to fifty per cent more intense than the current
cycle, reaching its peak in about 2012 (cycle twenty-four).
This could affect space satellites and any technology that relies
on them, as the sun’s energy output increases together with
perhaps a temporary increase in the Earth’s temperature during
this period.

Has the sun affected the Earth’s climate in the past?

While NASA satellites have been monitoring sunspot activity and
TSI since 1978, scientists and astronomers have been looking at
the sun through telescopes for almost 400 years, since shortly after
the telescope was invented.
As we know from Chapter H, the Earth entered a cooling period
about 1350–1850, which was termed the Little Ice Age. Temperature
drops around the globe were noticeable. Glaciers in the Alps
advanced, canals in Holland regularly froze and the Thames in
London would freeze over every twenty years or so.
During the coldest part of the Little Ice Age, between about
1645 and 1715, very low sunspot activity was observed.10
This period is called the Maunder Minimum, after the English
astronomer who made the observation.
Scientists now consider there is a link between the Little Ice Age
and the low level of sunspot activity recorded during that time.
So, it would seem that from scientific studies of the sun so far
that the sun’s irradiance may be slightly increasing by 0.05 per
cent each decade, which may have an effect on climate change
over timescales of 100 years or more.
The sun’s energy output may be responsible for causing or
contributing to the Little Ice Age, as very low sunspot activity
was observed for seventy years during the coldest part of this
period.

Is it the sun, yes or no?

While there is little doubt about the fact that global temperatures
have increased during the last 100 years, there is continuing
scientific debate in respect of the sun’s contribution to current
global warming.
According to the 2007 IPCC report, changes in solar irradiance
since 1750 are estimated to have caused a radiative forcing of 0.12
(+0.6 to +0.30) watts per square metre.
This is compared to a total net anthropogenic (manmade)
forcing of 1.6 (+0.6 to +2.4) watts per square metre.
Manmade radiative forcing is therefore much greater than the
effect the sun has had warming the Earth since the year 1750.
Radiative forcing is basically the change in the balance between
radiation entering the Earth’s atmosphere and leaving it. Positive
forcing will warm the Earth and negative will cool it.
It seems therefore that while the sun does of course have an
effect on the Earth’s climate, and therefore potentially global
warming, such effects are nowhere near as great as those of
anthropogenic or manmade causes, the burning of fossil fuels etc.
However, much longer studies will have to be made, it seems,
to determine the answer for sure!

Key points

➢ Light energy emitted from the sun, solar
irradiance, has increased by about 0.05 per cent
each decade from 1978, which could affect Earth’s
climate over the long term.
➢ The sun goes through solar cycles, which occur
every eleven years.
➢ Sunspot numbers represent the general level of
solar activity, with peak sunspot activity occurring
during solar maximum.
➢ During the coldest part of the Little Ice Age,
sunspot activity was observed to be at its lowest.
➢ While the sun does of course have an effect on
Earth’s climate, solar irradiance has had a radiative

Interested in reading more? Try the book…

A-Z of Global Warming – Free Saturday 4th February

4 Feb

Interested in climate change? Global Warming? The environment? If so, get your hands on a free copy of A-Z of Global Warming today! Educate your Kindle with an A-Z guide on the complex subject for FREE!

The Amazon and Global Warming

23 Jan

THE AMAZON

 

We start our A–Z journey on global warming with the Amazon Rainforest, which has an incredibly important role to play in maintaining balance in the Earth’s climate, in ways that are only just being understood. The Amazon is inextricably linked to the issue of global warming and therefore a very good place to start our inquiry into what may be the biggest threat to our existence on this planet.                              

 

AMAZON FACTS

 

The Amazon river basin contains the largest rainforest on Earth and covers approximately forty per cent of the South American continent. The rainforest is located in eight countries. Brazil has sixty per cent, with Colombia, Peru, Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guyana between them containing the rest. The Amazon forest is a natural reservoir of genetic diversity, containing the largest and most species-rich tract of tropical rainforest that exists. The Amazon contains an amazing thirty per cent of Earth’s species. One square kilometre can sustain about 90,000 tons of living plants! It’s also amazing to consider that one in five of all the birds in the world make the rainforest their home. The Amazon basin is drained by the Amazon River, the world’s second longest after the Nile. The river is essentially the lifeline of the forest. It is the most voluminous on Earth and its daily freshwater discharge into the Atlantic is enough to supply New York City’s freshwater needs for nine years! New measurements recently taken by scientists, however, suggest that the Amazon may actually be the longest river in the world. No doubt this will be confirmed if true, at some point in the future!

A few thousand years ago tropical rainforests covered as much as twelve per cent of the Earth’s land surface, but today the figure is below five per cent. The largest stretch of rainforest can be found in the Amazon river basin, over half of which is situated in Brazil.

 

Why is the Amazon so important in the context of global warming?

The rainforest acts as a major store of carbon and produces enormous amounts of oxygen. The Amazon has been referred to as ‘the lungs of the Earth’ because of its affect on the climate. The way this is achieved is of course through photosynthesis, the process by which green plants and trees use the energy from sunlight to produce food by taking CO2 from the air and water and converting it to carbon. The by-product of this is oxygen. The Amazon therefore helps recycle CO2 by turning it into oxygen, and it is estimated that the Amazon produces about twenty per cent of this essential gas for Earth’s atmosphere.

 

Trees, plants and CO2

Levels of CO2 in the atmosphere have been measured since 1958, from a monitoring station located on Mauna Loa volcano in Hawaii. They show sharp annual increases and decreases in CO2 levels, similar to the tooth on a saw. The readings seem to mimic a breath of air being taken in and out, almost as if the Earth is breathing. They correspond to the amount of vegetation on the planet (most of which is in the northern hemisphere, as the landmass there is greater), taking in CO2, and giving out oxygen. During summer in the northern hemisphere, when the Earth is tilted towards the sun, Earth’s vegetation is able to photosynthesise, resulting in an uptake of CO2, causing worldwide CO2 levels to drop. In winter in the northern hemisphere, when Earth’s axis is tilted away from the sun, the opposite happens, causing CO2 levels to rise again. When one becomes aware of the correlation between the Earth’s vegetation and CO2 levels, it is easy to understand why the Amazon, and rainforests in general, are such an important part of Earth’s ecosystem.

The problem is, however, that although the measurements taken at the volcano in Hawaii show sharp up and down annual readings, the measurements also show a simultaneous steady upward trend in CO2 levels. The importance of CO2 in relation to global warming will be a recurring theme throughout this book, and will be looked at further in Chapter C.

What has been happening in the Amazon?

A worrying trend is the Amazon having experienced two consecutive years of drought, in 2005 and 2006. The drought in 2006, which left rivers dry, stranded thousands of villagers, and put regional commerce at a standstill, was the worst on record. A second year of drought is of great concern to researchers studying the Amazon ecosystem. Field studies by the Massachusetts-based Woods Hole Research Centre in the USA, suggest that Amazon forest ecosystems may not withstand more than two consecutive years of drought without starting to break down. Severe drought weakens forest trees and dries leaf litter leaving forests susceptible to land-clearing fires set during the July-October period each year. According to the Woods Hole Research Centre, it also puts forest ecosystems at risk of shifting into a savannah-like state.

A recent experiment carried out by a team of researchers suspended 5,600 large plastic panels between 1 and 4 metres (3.2– 13.1 feet) above the ground to mimic severe drought conditions, where as much as eighty per cent of a one-hectare plot is deprived of eighty per cent of rainfall. Measuring rainfall, soil moisture, leaf and canopy characteristics over time, it was found that after four years the rainforest trees began to die while leaf litter dried and became tinder for wild fires.

Another factor is the El Niño Southern Oscillation (ENSO) event, a climatic phenomenon that influences much of the climate in the region, particularly Northeast Brazil, and the northern Amazon. ENSO brings with it dry conditions in the above areas, and manmade climate change is thought to increase this naturally occurring phenomenon in the future. ENSO is further looked at in Chapter W. Some climate models have suggested that temperatures in the Amazon may increase by 2 to 3°C (3.6–5.4°F) by the year 2050, together with a decrease in rainfall during the dry period. If the drought continues, based on the results of the aforementioned experiment, 2007/8 could be a turning point for the forest, which may mean that a tipping point will be reached where the forest will start to die, with catastrophic consequences for Earth’s climate. If this trend continues, according to the WWF, between thirty and sixty per cent of the Amazon rainforest could become dry savannah, rendering the forest a source of CO2 instead of a sink/store of it, which it currently is.

There are ways in which we can all help try and sustain this vast and ecologically important expanse of rainforest, and these will be discussed in Chapter Y. The Amazon will be further considered in Chapter D, where the problem of deforestation is looked at.

Key points

The Amazon rainforest contains about thirty per cent of Earth’s species.

World rainforest cover has over thousands of years decreased from twelve per cent to five per cent.

The Amazon helps to recycle CO2, a gas which contributes to global warming and while doing so produces about twenty per cent of Earth’s oxygen.

CO2 levels rise and fall with the seasons. There is greater landmass and hence vegetation in the northern hemisphere, which means that when Earth is tilted towards the sun during northern summertime, CO2 levels drop as a result of there being greater uptake of CO2 from photosynthesis. During the winter, the opposite happens and CO2 levels rise again.

Enjoy this excerpt? If so, download your copy of THE A-Z OF GLOBAL WARMING(US) (UK) now on Kindle or available on paperback.

Global Warming – A brief Introduction.

9 Sep

The term Global Warming has been in common usage for some time now and refers to recent warming of Earth’s atmosphere,which also implies a manmade or human influence.

Earth’s atmosphere comprises many gases: oxygen, nitrogen, carbon dioxide (hereafter abbreviated to CO2) and water vapour, to name a few. These gases are collectively called greenhouse gases and they keep the Earth’s temperature at a comfortable 15°C. Without them Earth would be a chilly -18°C.

Since pre-industrial times, usually taken to be before 1750, we know from ice-core records that CO2 levels were about 280 ppm,that’s 280 parts of CO2 per million parts of air. As industrialisation got underway humankind started to farm the land more intensely than ever before, which included deforestation for agriculture and settlements. Later – since about 1850 or so – the burning of fossil fuels for energy and transport has added considerably to greenhouse gas levels, particularly CO2.

This has resulted in CO2 levels increasing to about 390 ppm, a rise of about thirty-nine per cent from pre-industrial levels – mainly as a result of burning fossil fuels.

How do we know this?

Well, data from ice-core records that go back at least 650,000 years now show us that CO2 levels have fluctuated naturally during this time between 280 and 300 ppm. CO2 levels have also been measured accurately from the top of Mauna Loa Volcano in Hawaii since 1958, and results show an increase in CO2 levels from 315 ppm to 390 ppm since that time.

Therefore CO2 is now at ninety ppm more than it has been for at least 650,000 years of Earth’s history, and increasing. It is a known scientific fact that higher levels of greenhouse gases will lead to higher temperatures, which appears to be happening now. The world has warmed by an average of 0.74 degrees during the last 100 years or so. As a result of this warming, polar ice has started to decrease and melt, and so have Earth’s land-based glaciers. This in turn is causing sea levels to rise, which is putting low-lying islands at risk of flooding or total submersion, and will eventually threaten more and more of the world’s coastal cities and regions.

Things may get worse, however, because once Earth’s atmosphere starts to warm, the warming itself may cause further positive feedback mechanisms to kick in. A warmer atmosphere holds more water vapour, which is itself a powerful greenhouse gas. This will in turn cause further warming, and so on.

Melting ice results in more sunlight being absorbed by the surrounding ‘darker’ water and land, and that results in further warming, and more melting ice. Methane deposits currently held in a frozen but stable state under the sea and under the permafrost may be released as the oceans warm and permafrost melts, which will cause further warming. This is very worrying as methane is a potent greenhouse gas and around twenty times more powerful than CO2 when talking about it’s ability to warm the Earth’s atmosphere.

This is global warming in a nut shell, however there are of course far more complex issues involved as global warming will not affect the whole planet in the same way at the same time. Some parts will experience more drought, some parts more rainfall, and some parts more extreme weather such as floods and heatwaves.

One thing is for sure,as the world warms, we will all know about it…

For more information on the subject check out THE A-Z OF GLOBAL WARMING. Or visit my website SIROSSERTHRILLERS.

Hurricanes – Want To Know More?

28 Aug

As it’s 2011 Atlantic hurricane season until November, I have resurrected this article which explains what hurricanes are, how they form, and their relevance to global warming. Hurricane and typhoon are names given to a strong tropical cyclone. A ‘tropical cyclone’ is a generic term for a low-pressure system that has a definitive cyclonic surface-wind circulation.

Before considering the effects global warming may have on these weather systems, we will look at a few hurricane facts and figures. Depending where a cyclone occurs will determine whether it’s called a hurricane, typhoon or tropical cyclone. Hurricanes form in the North Atlantic and Northeast Pacific Oceans. Typhoons form in the Northwest Pacific area to the east of 160° longitude. Cyclones form in the Southwest Pacific Ocean, and the North and Southwest Indian Ocean. The Atlantic hurricane season, now underway, officially begins on 1st June and continues to the end of November each year. However, hurricanes do of course occur outside this time period. The seasons are different for Pacific and Indian Ocean areas, particularly the Northwest Pacific basin, where cyclones can occur all year round.

According to NOAA, hurricanes rotate in a counter-clockwise direction around a central ‘eye’, and a tropical storm will be classed as a hurricane only when wind speeds reach 74 mph (119 km/h) or more. Hurricanes can of course cause immense damage, especially if they hit land, where heavy rain, strong winds and especially strong waves – called the storm surge – can wreak destruction, as the unfortunate people of New Orleans found out during August 2005, when Hurricane Katrina hit with devastating consequences.

Hurricane strength is measured using the Saffir-Simpson scale, named after two engineers from the US National Hurricane Center, who developed it in 1969. The scale is used only to describe hurricanes that form in the Atlantic and Northeast Pacific basins. The scale has five intensities depending on wind speed. For example, a category one hurricane has a wind speed of 74 mph (118 km/h) and a category five hurricane 156+ mph (251 km/h). Hurricane Katrina, mentioned above, was probably the most devastating storm in US history, causing an estimated $100,000,000,000-worth of damage. Katrina was a category five storm, but dropped to a three when it hit land on the eastern seaboard of the USA, in August 2005.

For hurricanes to develop, certain environmental conditions must be present, such as warm ocean water, high humidity and favourable atmospheric and upward spiralling wind patterns off the ocean surface. Atlantic hurricanes usually start off as a weak tropical disturbance off the West African coast, and intensify into rotating storms with weak winds called tropical depressions. It’s only when wind speeds reach at least 74 mph (118 km/h) that they are classified as hurricanes. NASA scientists and NOAA have been studying how winds and dust conditions from Africa influence the birth of hurricanes in the Atlantic Ocean, using an armoury of NASA’s Earth observing satellites. It seems that NASA is on course to establish whether or not global warming is indeed influencing the weather. NASA’s AIRS instrument on board the Aqua satellite, which is short for Atmospheric Infrared Sounder, can measure very subtle changes in the Earth’s climate. Scientists from NASA and NOAA, as well as other scientists, have already demonstrated that AIRS data can lead to better forecasts about the location and intensity of ‘extratropical cyclones’, which are mid-latitude storms, often striking the east coast of the USA. This may enable the team to test the climate-weather hypothesis once more data is available. AIRS will also have the ability to test the hypothesis that climate change may be causing the water (hydrological) cycle to accelerate, by measuring the humidity distribution within the atmosphere.This will show with sufficient accuracy whether the water cycle is indeed speeding up. If so, as is suspected in a warmer world, there will be more water vapour and clouds in the atmosphere resulting in more rainfall. If so, AIRS will be able to establish a link between global warming and the weather, as a faster water cycle causes greater rainfall as a result of an accelerated hydrological cycle.

2005 was the most active hurricane season since reliable records began, with fifteen hurricanes, seven of which were major ones.

This article was taken from my book, THE A-Z OF GLOBAL WARMING. Download the book from Amazon USA or Amazon UK on Kindle for further information like this. Alternatively, for a fast-paced action-adventure thriller with an eco theme, try TIPPING POINT. US readers can go to Amazon USA, and UK readers Amazon UK.