Environment Archives

May 1, 2008December 24, 2015 by Ian O'Neill

Ocean Currents May Cool the Climate for a Decade

False-color image of the temperature of the Gulf Stream off the East Coast of the US (NASA)

It would appear that rising atmospheric temperatures may be slowed or even stopped over the next ten years due to periodic changes in ocean circulation. As the Gulf Stream slows the flow of warm tropical waters from the equator to the North Atlantic, North America and Northern Europe will experience a slight reduction in atmospheric temperatures. This appears to be a natural process that has occurred in historic records. But don’t go getting too excited, this will only pause the global warming trend at best. The UN’s Intergovernmental Panel on Climate Change (IPCC) forecasts a global temperature rise of 0.2°C (0.36°F) per decade, and this trend will continue after the currents have settled…

The oceans are the planets huge heaters and refrigerators. Within the oceans are complex and highly dynamic flows of warm and cool streams. One stream in particular, the Gulf Stream, reaches from the tropical waters of the Gulf of Mexico to the cold waters of Northern Europe. As the tropical stream of water travels north and cools, it sinks and flows back in the opposite direction, carrying the cold North Atlantic water south. This ocean “conveyor belt” maintains the surprisingly warm weather systems that Europe experiences. Without this supply of ocean heat, countries at these high latitudes (like the UK where weather systems are dominated by ocean conditions) would experience the harsh winters more associated with Moscow.

So, in research published in Nature on Thursday, it would seem the North Atlantic is about to get a little cooler. Mojib Latif, professor at the Leibniz Institute of Marine Sciences in Kiel, northern Germany and his team predict a cooling in North American and European regions, whilst the temperatures of tropical regions will be stabilized. Scientists have known about the weakening of the Gulf Stream for a long time, but this is one of the first studies to demonstrate how this process may influence global temperatures and how global warming isn’t necessarily a gradual increase. But there’s a catch. This trend can only be sustained for ten years, after which atmospheric global warming will continue to increase at the IPCC rate. The German scientists are clear that they are not disputing the IPCC figures:

“Just to make things clear, we are not stating that anthropogenic [man-made] climate change won’t be as bad as previously thought. What we are saying is that on top of the warming trend, there is a long-periodic oscillation that will probably lead to a lower temperature increase than we would expect from the current trend during the next years.” – Mojib Latif

This work predicts that the Gulf Stream will slow over the next few years, but other studies argue change is happening now. The saltiness of the Atlantic waters is also a concern. Due to the huge input of fresh melt water from Greenland’s glaciers and Siberian permafrost over the past few years, the stream has been strongly affected. It would appear there are many factors when considering how these vast currents can be influenced.

There is a warning in this new study. The weakening of the Gulf Stream is part of a natural oscillation. We may be facing a weakened stream over the next ten years, cooling the climate, but there will also be a strengthening of ocean currents in the future. What happens when the stronger currents begin heating North Atlantic waters?

Source: Physorg.com

April 29, 2008December 24, 2015 by Ian O'Neill

Global Warming is Accelerating Faster than can be Naturally Repaired

It appears the Earth’s climate has the ability to naturally regulate atmospheric carbon dioxide levels. Historic records extracted from ice cores show quantities of CO₂ have varied widely in the last hundreds of thousands of years. This evidence appears to support the global warming critics view that current observations of the human-induced greenhouse effect is actually naturally occurring and the effects of carbon on the climate is over-hyped. However, a new study shows that although carbon dioxide levels may have been larger in the past, the Earth’s natural processes had time to react and counteract global warming. The current trend of industrial emissions has been far more accelerated than any historic natural process, natural climate “feedback loops” cannot catch up to remove CO₂ from the atmosphere.

More bad news about the outlook for our climate I’m afraid. It would appear that the carbon dioxide emissions we have been generating since the Industrial Revolution have increased too rapidly for the Earth’s natural defences to catch up. This new finding comes from the analysis of bubbles of air trapped in ancient ice in Antarctica, dated to 610,000 years ago.

Long before man started burning coal and oil products, the Earth would naturally generate its own carbon emissions. The main polluters were volcanic eruptions, sending millions of tonnes of carbon dioxide into the atmosphere. Surely this had an effect on the state of the climate? Apparently so, but the increased levels of carbon dioxide produced by individual eruptions could be dealt with naturally over thousands of years. The climate wants to be in balance, should one quantity increase or decrease, other mechanisms are naturally triggered to bring the system back into equilibrium.

These mechanisms are known as “feedback loops”. Feedback loops are common in nature, should one quantity change, production of other quantities may speed up. In the case of the carbon emission from volcanic activity, levels of the stuff appear to have been controlled by a natural “negative feedback” loop (akin to a carbon thermostat, when carbon dioxide levels were too high, another process was triggered to remove the carbon dioxide from the atmosphere). However, the sustained atmospheric input of industrial burning of carbon dioxide by human activity has dwarfed historic volcanic carbon output, overwhelming any natural negative feedback mechanism.

This new study is published in the journal Nature Geoscience and carried out co-author Richard Zeebe. In an interview at the University of Hawaii, Zeebe comments on the climate’s ability to remove carbon dioxide from the atmosphere: “These feedbacks operate so slowly that they will not help us in terms of climate change […] that we’re going to see in the next several hundred years. Right now we have put the system entirely out of equilibrium.”

Zeebe and his team noticed that the levels of carbon dioxide and atmospheric temperature correlated, rising and falling together. “When the carbon dioxide was low, the temperature was low, and we had an ice age,” he said. His study states that in the last 600,000 years the carbon dioxide levels have fluctuated only by 22 parts per million. Since the 18th century, human activity has injected 100 parts per million. Humans have increased the quantity of carbon dioxide 14,000 times more than any natural process is capable of doing. This increase has negated any chance for the climate to naturally bring carbon dioxide levels back down to pre-industrial levels in the short term. If we were to stop all emissions tomorrow, it would take the planet hundreds of thousands of years to recover naturally.

Sadly, we’re not even close to slowing carbon emissions. Only last week, the US reported that carbon dioxide levels were up 2.4 parts per million during 2007 alone. The future is bleak for the planet balancing back into its prehistoric atmospheric carbon equilibrium…

Source: Reuters

April 3, 2008December 24, 2015 by Ian O'Neill

There is No Sun-Link with Global Warming

The connection between solar activity and global warming has been a contentious issue for a long time. The idea that cosmic rays create global cloud cover just doesn’t seem to be working out; even the highest estimates of cloud cover variation caused by cosmic ray flux predict the effect to be very small. Now UK scientists have stepped into the debate, producing scientific evidence that there is no link between global warming, cosmic rays and solar activity. Sorry global warming sceptics, we might have to cut back on the emissions after all…

The connection between solar activity and global warming is thought to go like this: The Sun experiences massive changes in energy output throughout the 11-year solar cycle. At its peak (at solar maximum), the Sun’s influence over local space is at its highest. Its massive magnetic field will envelop the Earth and spiral into interplanetary space. As it does so, the immense and large-scale solar wind will deflect high energy cosmic rays. So, counter-intuitively, when the Sun is at its most active, cosmic ray collisions with the atmosphere is at its lowest. It is has been predicted by scientists such as Henrik Svensmark at the Danish National Space Center (DNSC) that these high energy cosmic rays will impact the Earth’s atmosphere, create droplets of water, thus generating cloud cover. So, following this logically, we should have a global decrease in cloud cover during periods of high solar activity (when cosmic rays are not deflected by the solar wind), causing global warming (as there will be less clouds to reflect the solar radiation). Many of the climate problems we are having at the moment can then be attributed to the Sun and not human activity.

But there’s a problem. As previously reported by the Universe Today, research groups will often publish conflicting results about the cosmic ray effect on cloud production. In one of the most definitive results to come out of this area of study has just been announced by UK scientists, and guess what? The Sun/cosmic-ray theory has no measurable effect on the climate change we are currently experiencing.

Dr. Svensmark’s idea was central to the science behind the documentary “The Great Global Warming Swindle” where the human impact on global climate change was brought into question. This theory has been under fire since its conception by highly regarded scientists such as Mike Lockwood from the UK’s Rutherford-Appleton Laboratory. Svensmark stands by his work. So with this in mind, Dr. Terry Sloan from Lancaster University set out to prove Svensmark’s hypothesis. But the results aren’t pretty.

“We tried to corroborate Svensmark’s hypothesis, but we could not […] So we had better carry on trying to cut carbon emissions.” – Dr. Terry Sloan

In a separate study, Giles Harrison from Reading University, also studied the effect of cosmic ray flux on the amount of cloud cover, stating it is an important area of research, “…as it provides an upper limit on the cosmic ray-cloud effect in global satellite cloud data“. Although restricted to the atmosphere above the UK, Harrison’s study also returns the verdict that there is only a very weak cosmic ray effect on cloud production.

The Intergovernmental Panel on Climate Change (IPCC) released a report last year pointing the finger at human activity as the root cause behind global warming. There are very strong correlations between carbon emissions and global warming since the 1970s, so the IPCC has strongly recommended that the international community make radical cuts to their carbon emissions. What’s more the IPCC point out that the contribution from greenhouse gas emissions outweighs the effect of solar variability by a factor of 13 to one.

“…as far as we can see, he has no reason to challenge the IPCC – the IPCC has got it right.” – Dr. Terry Sloan

Source: BBC

March 28, 2008December 26, 2015 by Tammy Plotner

Darkness Washes Around The Globe As Earth Hour Descends

earthhour_wideweb__470x4410.thumbnail.jpg

35 countries, 26 major cities, 370 towns and literally tens of millions of people… What do they all have in common?

They’re all switching off their lights for one hour at 8:00 pm local time in a now staggering global event known as Earth Hour. From around the world, Universe Today readers made a huge impact.

For all of you who took the time to sign up for Earth Hour, I not only thank you for your participation, but have deeply enjoyed watching our effort expand over the last week. We literally melted down the server on our personal UT Earth Hour site with our responses! What a tremendous effort on all our parts.

In a matter of hours, and quite probably by the time you read this, the lights will begin to go down as Earth Hour descends. As darkness falls in Australia, city landmarks from Parliament House in Canberra to the Sydney Harbour Bridge, Melbourne’s Federation Square and the WACA ground in Perth will power down for an hour. Landmarks, cities and communities around the world will go dark – one by one – as Earth Hour reaches each time zone.

Says Earth Hour’s executive director Andy Ridley:

“Earth Hour is about everyone and every organisation, from individuals to global companies, joining together to own a shared problem – climate change. Governments and businesses are joining individuals, religious groups, schools and communities in this terrific movement that’s all about making a change for the better. It’s staggering to see so much support from across the globe.”

Can you picture yourself high above the Earth as city after city and home after home turn off the lights not long after the terminator of night has passed? As darkness washes around the globe, our voices will be heard – as well as seen – for anyone who cares to look.

If you won’t participate in Earth Hour simply because you don’t think it will make a change, then do so for astronomers who are celebrating the beginning of National Dark-Sky Week. How will it reduce light pollution, given that it only lasts a week and not everyone will participate? The main goal of NDSW is to raise awareness about the harmful effects of light pollution. It just isn’t possible for all of the light pollution in the world to disappear, but together we can. make difference, just like Earth Hour, and inspire us all to preserve the beauty of the night sky.

One thing is for certain, Earth Hour is huge news. And all of us here at Universe Today can be very proud that we are part of it.

March 22, 2008April 26, 2016 by Tammy Plotner

Countdown to Earth Hour 2008…

Do you remember last year when Sydney, Australia made the news by turning their lights out for one hour to show their concern about global warming? Besides being concerned about the effects, especially for my children and grandchildren, as an astronomer I support anything which helps reduce light pollution, even if it’s just for an hour. Beyond extinguishing the lights for 60 minutes at 8pm March 29, 2008, there are lots of things you can do to make Earth Hour 2008 an even greater success. Let’s take a look.

2.2 million people and 2100 Sydney businesses turned off their lights for one hour – Earth Hour – March 29, 2008. According to their information, the greenhouse reduction achieved in the Sydney CBD during Earth Hour was sustained for a year, it would be equivalent to taking 48,616 cars off the road for a year. This year many major global cities are joining Earth Hour in 2008, and they’re are turning a symbolic event into a global movement.

Start showing your support by visiting our own Universe Today Earth Hour page and signing up on the UT page. You’ll see your name appear as an Earth Hour / Universe Today participant! Tell a friend. Better still, tell all your friends, and your family, and your workmates. Just email them with a link to this website. We may or may not make an impact, but it won’t be because we didn’t try. You can also organize your own Earth Hour activities as well and you’ll find packets and information on how to involve your community at the Earth Hour Website.

If you think this is going to be big, then you’re right. Created to take a stand against the greatest threat our planet has ever faced, Earth Hour uses the simple action of turning off the lights for one hour to deliver a powerful message about the need for action on global warming. This simple act has captured the hearts and minds of people all over the world. As a result, at 8pm March 29, 2008 millions of people in the world’s major capitol cities like Aalborg, Aarhus, Adelaide, Atlanta, Bangkok, Brisbane, Canberra, Chicago, Christchurch, Copenhagen, Dublin, Manila, Melbourne, Montreal, Odense, Ottawa, Perth, Phoenix, San Francisco, Suva and Lautoka, Sydney, Tel Aviv, Toronto and Vancouver will be participating as well.

At last count, over 172,000 individuals and nearly 12,000 businesses/organizations have agreed to support Earth Hour. Just who in the astronomy world would do that? In the United States alone you’ll find such great organizations Adler Planetarium, Arizona Science Center, Oceanside Photo and Telescope, StarPals, and The Chicago Astronomer just to name a few. You’d be amazed at the number of schools, universities, restaurants, motels, airlines and others that will be participating.

March 20, 2008December 26, 2015 by Ian O'Neill

Could Cosmic Rays Influence Global Warming?

The idea goes like this: Cosmic rays, originating from outside the Solar System, hit the Earth’s atmosphere. In doing so these highly energetic particles create microscopic aerosols. Aerosols collect in the atmosphere and act as nuclei for water droplet formation. Large-scale cloud cover can result from this microscopic interaction. Cloud cover reflects light from the Sun, therefore cooling the Earth. This “global dimming” effect could hold some answers to the global warming debate as it influences the amount of radiation entering the atmosphere. Therefore the flux of cosmic rays is highly dependent on the Sun’s magnetic field that varies over the 11-year solar cycle.

If this theory is so, some questions come to mind: Is the Sun’s changing magnetic field responsible for the amount of global cloud cover? To what degree does this influence global temperatures? Where does that leave man-made global warming? Two research groups have published their work and, perhaps unsurprisingly, have two different opinions…

I always brace myself when I mention “global warming”. I have never come across such an emotive and controversial subject. I get comments from people that support the idea that the human race and our insatiable desire for energy is the root cause of the global increases in temperature. I get anger (big, scary anger!) from people who wholeheartedly believe that we are being conned into thinking the “global warming swindle” is a money-making scheme. You just have to look at the discussions that ensued in the following climate-related stories:

But what ever our opinion, huge quantities of research spending is going into understanding all the factors involved in this worrying upward trend in average temperature.

Cue cosmic rays.

Researchers from the National Polytechnic University in the Ukraine take the view that mankind has little or no effect on global warming and that it is purely down to the flux of cosmic radiation (creating clouds). Basically, Vitaliy Rusov and colleagues run the analysis of the situation and deduce that the carbon dioxide content of the atmosphere has very little effect on global warming. Their observations suggest that global temperature increases are periodic when looking into the history of global and solar magnetic field fluctuations and the main culprit could be cosmic ray interactions with the atmosphere. Looking back over 750,000 years of palaeotemperature data (historic records of climatic temperature stored in ice cores sampled in the Northern Atlantic ice sheets), Rusov’s theory and data analysis draw the same conclusion, that global warming is periodic and intrinsically linked with the solar cycle and Earth’s magnetic field.

But how does the Sun affect the cosmic ray flux? As the Sun approaches “solar maximum” its magnetic field is at its most stressed and active state. Flares and coronal mass ejections become commonplace, as do sunspots. Sunspots are a magnetic manifestation, showing areas on the solar surface where the powerful magnetic field is up welling and interacting. It is during this period of the 11-year solar cycle that the reach of the solar magnetic field is most powerful. So powerful that galactic cosmic rays (high energy particles from supernovae etc.) will be swept from their paths by the magnetic field lines en-route to the Earth in the solar wind.

It is on this premise that the Ukrainian research is based. Cosmic ray flux incident on the Earth’s atmosphere is anti-correlated with sunspot number – less sunspots equals an increase in cosmic ray flux. And what happens when there is an increase in cosmic ray flux? There is an increase in global cloud cover. This is the Earth’s global natural heat shield. At solar minimum (when sunspots are rare) we can expect the albedo (reflectivity) of the Earth to increase, thus reducing the effect of global warming.

This is a nice bit of research, with a very elegant mechanism that could physically control the amount of solar radiation heating the atmosphere. However, there is a lot of evidence out there that suggests carbon dioxide emissions are to blame for the current upward trend of average temperature.

Prof. Terry Sloan and Prof. Sir Arnold Wolfendale from the University of Lancaster and University of Durham, UK step into the debate with the publication “Testing the proposed causal link between cosmic rays and cloud cover“. Using data from the International Satellite Cloud Climatology Project (ISCCP), the UK-based researchers set out to investigate the idea that the solar cycle has any effect on the amount of global cloud cover. They find that cloud cover varies depending on latitude, demonstrating that in some locations cloud cover/cosmic ray flux correlates in others it does not. The big conclusion from this comprehensive study states that if cosmic rays in some way influence cloud cover, at maximum the mechanism can only account for 23 percent of cloud cover change. There is no evidence to suggest that changes in the cosmic ray flux have any effect on global temperature changes.

The cosmic-ray, cloud-forming mechanism itself is even in doubt. So far, there has been little observational evidence of this phenomenon. Even looking at historical data, there has never been an accelerated increase in global temperature rise than the one we are currently observing.

So could we be clutching at straws here? Are we trying to find answers to the global warming problem when the answer is already right in front of us? Even if global warming can be amplified by natural global processes, mankind sure ain’t helping. There is a known link between carbon dioxide emission and global temperature rise whether we like it or not.

Perhaps taking action on carbon emissions is a step in the right direction while further research is carried out on some of the natural processes that can influence climate change, as for now, cosmic rays do not seem to have a significant part to play.

Original source: arXiv blog

March 19, 2008December 26, 2015 by Ian O'Neill

Gravity Waves in the Atmosphere can Energize Tornados (Video)

Gravity waves are global events. Much like the ripples on a massive pond, these large-scale waves can propagate from an atmospheric disturbance over thousands of miles. These waves are maintained by the gravitational force of Earth pulling down and the buoyancy of the atmosphere pushing up. Until now it has been hard to link atmospheric gravity waves with other atmospheric phenomena, but new research suggests that gravity waves passing over storms can spin up highly dangerous and damaging tornados… Suddenly gravity waves become very important and may help to forecast where and when tornados may strike…

In a nutshell, meteorologist Tim Coleman of the National Space Science and Technology Center in Huntsville (Alabama) sums up what gravity waves are:

“They are similar to waves on the surface of the ocean, but they roll through the air instead of the water. Gravity is what keeps them going. If you push water up and then it plops back down, it creates waves. It’s the same with air.” – Coleman

A large number of things may cause gravity waves (not to be confused with gravitational waves, the ripples in space-time), including intense disturbances caused by storm systems, a sudden change in jet stream location or wind shear. The strong oscillation will then travel for hundreds or even thousands of miles.

See a gravity wave in action over Iowa…

Far from gravity waves being a mild curiosity, it seems that they have a large part to play with other atmospheric dynamics down here on the ground.

Tim Coleman and colleagues have found that the passage of gravity waves over the top of storms could intensify or even create tornados. It is all down to the angular momentum of the spinning storm. When storms are large, they slowly rotate. If for some reason they shrink in scale, the spin will increase (imagine an ice-skater spinning on the ice with her arms outstretched, as she brings her arms in, she spins faster). This is the fundamental rule of angular momentum conservation, as the size of a storm contracts, the faster it spins. Ultimately, if the conditions are right, intense tornados can be generated, a huge amount of angular momentum in a tiny volume.

Now gravity waves are believed to have a part to play. As they pass over a storm, the pressure of the overlying gravity wave propagation will compress the storm. As this occurs, a vast amount of angular momentum is forced into a smaller volume. The seeding of baby tornados is therefore possible. Gravity waves also come in sets; one wave will follow another, each periodically compressing the storm, intensifying tornado generation.

So keep your eyes peeled for incoming gravity waves during a storm… tornados may spin to life…

Source: NASA

March 19, 2008December 26, 2015 by Fraser Cain

Arctic’s Oldest and Thickest Ice is Melting Away

It’s been a strange year for the Arctic. During the summer, high temperatures melted away vast regions of the Arctic sea ice, opening up the Northwest Passage for the first time. But then this winter has been unusually cold, bringing back large large areas of sea ice. So what’s going on? Is the Arctic recovering, or is Global Warming marching on?

The big problem studying global warming is that the temperatures and local climate can fluctuate. Over the short term, in some regions, you can have unseasonably warm or cold temperatures. Here in Vancouver, we had one of the coldest, snowiest winters I’ve ever seen.

NASA scientists are measuring the long term trends for the ancient perennial sea ice that lasts across several seasons. And this ice seems to be melting away over the years. In the past, this perennial sea ice – anything that lasted more than a single year – covered 50-60% of the Arctic. This analysis was made by NASA’s ICESat satellite, which measures sea ice thickness with microwaves.

This year, the perennial sea ice covered only 30% of the Arctic. And the most ancient ice, that which has survived more than 6 years, used to comprise 20% of the Arctic. Now it’s down to just 6%.

As this year shows, Arctic sea ice doesn’t stand still. Its coverage grows and declines seasonally, reaching the maximum in March, and the minimum in September. And this year, the maximum is up 3.9% over the previous 3 years. At the same time, the perennial sea ice coverage is down to an all-time minimum.

As the perennial sea ice thins, it’s more vulnerable during the summer melt period to wind and waves. Large chunks of ice can be carried out of the Arctic to melt in warmer waters.

Don’t worry about water levels rising as the sea ice coverage disappears. This ice is already in the water, displacing the same amount. So as it melts, sea levels should stay right where they are. That’s different from the ice locked up in the world’s glaciers, Greenland, and the Antarctic ice cap. As those melt, sea levels will rise.

To better understand the Arctic ice coverage, NASA is planning to launch a follow-on mission called ICESat II, due for launch in 2015.

Original Source: NASA News Release

March 5, 2008December 26, 2015 by Tammy Plotner

Measure Light Pollution and Help Save Our Dark Skies

It’s a stunning photo… And one we all recognize. At this point in time, more than half of the Earth’s population lives in or near a city and the results shine clearly from space. The crime is not energy consumption, over-population or even global warming. It’s the loss of one of our greatest natural resources… The starry night sky.

Light pollution effects more than just our ability to see the stars at night. Take a walk along the coastlines. It may be hard to believe, but hatching sea turtles aren’t able to get their bearings due to beachfront lighting. Even the aquatic ecosystems are effected! But it’s not just at the waters edge. Birds find it difficult to make
nesting choices and many species have difficulty breeding under over-lighted conditions. Can you imagine how much light changes disturb the habits of nocturnal animals and night-loving plants? Just as important and the Sun shining its life giving light on the Earth, so we are balanced by darkness.

I’m not hear to preach to you about light pollution. Outdoor lighting is used for many reasons, like security, sporting events and even advertising. However, by making just a few small changes – intelligent choices – on how we use that light we can help to preserve the stars for generations to come. You can learn more just by visiting the International Dark Sky Association and taking a few minutes to read.

Right now, you can do science a favour just by taking a few minutes out of your evening and having a look at the night sky from your location. It’s just as easy as finding Orion and counting the stars you see! In a effort to collection information from people the world over, GLOBE (Global Learning and Observations to Benefit the Environment) is asking for your help. It’s a great way for teachers, students, parents and even people just like you and me to participate in a real science effort. Visit the G.L.O.B.E. at Night pages for more information and join us in a world-wide effort!

February 21, 2008December 26, 2015 by Ian O'Neill

Solar Variability Most Likely Not the Cause of Global Warming

The gradual increase in global temperatures is getting harder and harder to pin on the Sun and its energy output variability. The Sun hasÂ a variationÂ in how much energy it outputs but this variability is only about one tenth of one percent. The pattern of atmospheric heating since the 1960s is showing an increase with the increase inÂ human activity (industry, transportation, power generation)Â and neither are showing signs of slowing down…

At the American Association for the Advancement of Science (AAAS) meeting in Boston, many talks are focusing on climate change and the human impact on the Earth. Experts in solar science, climate modeling, and atmospheric science are exploring the issues surrounding what the main culprit behind the rapid rate of change in global temperatures could be. The sole energy input into the Earths atmosphere comes from the Sun; so many scientists have looked toward our star for the answers. The Sun does vary its output of energy (historically, this is obvious during long periods of solar inactivity, such as the Maunder Minimum in the 1600’s where hardly any sunspots were observed on the Sun – this reduction in activity has been linked to the “Little Ice Age” experienced during this time), but generally speaking, the net energy increase or decrease is very small.

The link between solar variability and global warming has taken another blow from analysis of historical samples of sediment containing radioactive carbon-14 and a beryllium isotope. Quantities of carbon-14 and beryllium-10 reflect solar activity as they are greatly affected by solar magnetic field strength. The Sun’s magnetic field is directly related to solar activity (and therefore sunspot population). These radioactive isotopes are created by the impact of cosmic rays in the Earths atmosphere, and should the solar magnetic field be strong (i.e. during periods of high activity), cosmic rays will be blocked, reducing the quantity of isotopes in the sediment.

However, results from this analysis appear inconclusive and no strong link can be found in favour of increased solar activity during periods of atmospheric heating.

Linking any atmospheric phenomenon with solar variability is a difficult task. Attempts to connect monsoons with the 11-year solar cycle for instance have failed in 150 years of trying. It would seem that, for now at least, any connection between increased solar energy output and global warming is tenuous at best.

Casper M. Ammann, climate modeler at the National Center for Atmospheric Research in Boulder, Colorado, points out that global temperatures are rising at a historic rate, and there remains no link between solar variability and global warming. He states that global warming has “nothing to do with changes in solar activity. Itâ€™s greenhouse gases. Itâ€™s not the sun that is causing this [climate] trend.”

Perhaps the only answer is to drastically cut back our dependence on fossil fuels to slow the rate of carbon dioxide production. Even if the Sun should decide to become inactive, as there appears to be very little relationship between solar output and global warming, we will not be able to escape the greenhouse gases heating up our climate.

Source: Physorg.com