Climate Change

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Ordovician Extinction: 440 mya

Devonian Extinction: 360 mya

Permian Extinction: 250 mya

Triassic Extinction: 210 mya

Cretaceous Extinction: 65 mya

Doomsday Asteroid, year AD 20??

Climate Change

We embraced the technology that developed from the industrial revolution of the mid 19th century. It changed our lives for the better. It’s called progress. However we didn’t realise that it was also changing/transforming our planet for the worse. So everything we grew up to value, our material possessions that we became so dependent on, we have now come to realise that they are threatening the future of the planet (in terms of what?)

Is it possible to just slightly change our lifestyles and retain a good quality of life and reduce sufficiently carbon emissions, or will it require drastic changes, certainly the later we leave it to change behaviours the more drastic the change required.

What does climate change mean. Unusual weather patterns have increased. Expect the unexpected. Since the 1970s we have seen extreme weather event – natural? catastrophes like (droughts, tornados, hurricanes, flooding, fires) have multiplied all over the planet.

As Global citizens we need to act and act fast. Brace for calamity. How much do we need to alter our lifestyles to reduce the co2 emissions?

Can we remove carbon dioxide from the atmosphere

400 parts per million – the threshold and then climate change becomes irreversible

Is this Nature’s hitting back at humans, Nature’s response to what has become the human scourge/plague/curse

What is now clear is that the emission of greenhouse gases is causing global warming at a rate that began as significant, is now alarming and is unsustainable in the long term.

How do you persuade people, all the planets inhabitants, that this is real – this surely is the biggest challenge facing the planet

What energy needs can renewable energy meet?

According to James Lovelock – Gaia – Nuclear is the only short term solution – look at it like a bandage, until we find another means. The side effects of Nuclear, the collateral damage, from leaking radiation, nuclear accidents is negligible when you compare it to what will happen after we reach the 400 ppm threshold.

Can governments be trusted with running a nuclear power program. Remember the soviets waited 36 hours to evacuate Chernobyl and waited even longer to tell the rest of the world.

A nuclear pompey- The city of Prypiat in the Ukraine and many of the towns around Chernobyl – which is a place frozen in time – are now overgrown by vegetation and wildlife.

Reasons against Nuclear – history shows that it pollutes the environment with very toxic and dangerous substances, history shows us that after 50 years of generating nuclear waste and we still don’t know what to do with it and that material will remain dangerous for ¼ million years.

The billions living in the developing world of China and India are only now beginning to follow western civilization in terms of energy usage, ie, powered by fossil fuels, there economies are expanding at incredible rates – but the harder they work to strengthen their economies and drag themselves out of poverty the more certain they are of bring about their own destruction.

Our Sun

The sun is much more than just a giant light bulb. There are other forces at work in the sun. Forces that change over minutes and over years, forces that tear the surface apart. We are only now beginning to understand these forces and the effect they have on the earth. But we’ve known about them for 100s of years. Because the sun gets spots. These are a tell tale sign.

Sunspots are dark regions on the surface of the Sun. Typically about the size of the Earth. With the resolution in our telescopes today we can see detailed structures in the sunspots. The umbra and penumbra. The spots are not static. Movements of sunspots have been studied for about 400 years. Ever since Galileo trained his telescope on the sun and made the first crucial discovery about it’s behaviour. Actually the first people to record sunspot activity were the ancient Chinese, who could observe them through thin cloud, long before Galilleo.

Galileo was surprised to see black dots creeping over the surface so he kept track of them over a number of days and found that they were all moving in the same direction. To Galileo the meaning was clear, the sun was rotating and was turning faster at the equator than at the poles. Ever since Galileo, records have been kept of the comings and goings of sunspots and variations soon became clear. Sometime the sun is covered in 100s of spots. Other times there are none at all. And after a while a pattern emerged.

Sunspots appear darker because they are about four thousand degrees, which is two thousand degrees cooler than the surrounding area. They are the result of magnetic activity within the Sun. They are telltale points where the magnetic field lines break through the sun's surface. Somehow the magnetic field lines insulate the the gas in the center from the surrounding gas so there is a temperature differential of about two thousand degrees and the sunspots appear darker only relative to the surrounding area, remember a sunspot is about four thousand degrees.

If you observe sunspots over a period of years, they come and go with about an eleven year cycle. Until recently no one new what was driving the solar cycle or where sun spots came from. But people had always suspected that these scars on the suns surface had some sort of an effect on the earth, but nobody could put there finger on what it was. One effect sunspots do have on the earth is on the climate. But it is a subtle effect, its greatest impact was only noticed 300 after the event. It was discovered in Greenich by astronomer Robert Maunder who was studying the 100s of years of sunspot records held at the royal observatory He discovered that there had been this peculiar effect in the 2nd part of the 17th and 18th century’s where sunspot numbers diminished to a a fraction of what they are today, and he described this as the Maunder minimum. For 70 years, from 1645 to 1715, sunspots disappeared, it was as if the engine that drives the solar cycle had stopped. And it correlated almost exactly with the last period of prolonged cold to strike the northern hemisphere. They call it the little ice age.

Soho - the solar and helispheric observatory – is the most used of all the solar telescopes to observe the sun. It sits at the Earth-Sun L1 point about a million miles from earth,, where the gravitational total pull from the earth and sun are equal. It has an uninterrupted view of the Sun and its surroundings giving us continuous data from the Sun since 1995. It has played a key role in understanding the explosive power of the sun. It reveals solar flares and CME which erupt from sunspots, temperature of some of the flares is about 10,000,000 degrees. At solar max the sun puts on the best fireworks display in the solar system.

Other important solar observatories are the SDO (Solar Dynamics Observatory), recently launched into geosynchronous orbit. SOLO (Solor Orbiter), planned to be launched in 2015. HINODE, launched in 2006.

Solar astronomers are now beginning to understand the cause of these eruptions. It’s due to magnetism, it has a complex magnetic field. The sunspots are the regions of the strongest magnetic field in the sun. Sunspots are just the visible effect of the magnetic fields of the sun so strong that they can prevent the heat and light rising from the interior. With the right viewing equipment you can even see the magnetic fields.

Magnetic loops arch of the surface. Like iron filings around a bar magnet, there shapes are mapped out by plasma heated to a million degrees. Some arches are 200,000 km high. The loops are caused by the twisting of the suns basic magnetic field.

Because the sun rotates faster at the equator than the poles it drags the field lines with it. The fields get more and more twisted, and break through the surface. Until at solar max when the whole sun is covered in loops and stretched to breaking point. Solar flares are what happens when the strain gets too much, and the loops snap. Basically all that energy comes out of the catastrophic release of energy that has been stored in the magnetic field. When the energy bound within sunspots is released it fires billons of tonnes of plasma far into space at huge speeds. And sometimes they are aimed straight at the earth. The flares fly thru space fror 2 days. When they reach us the earths own magnetic fields deflects most of the glow. But some of this 'space weather' as its often called does get thru, in the magical displays called the aurora. These dancing displays of celestial light are caused by particles from the solar storm smashing through the magnetic fields at the poles. When they strike the upper atmosphere they light up the polar skies. But the buffeting of the magnetic fields can have unseen effects. Migrating animals that use the magnetic fields can lose their bearings. Homing pigeons don’ come home. And whale strandings have been seen to increase with solar activity. But most worryingly for us is the effect that the disrupted magnetic field can have on electronics. The strongest storms can damage or destroy satellites with devastating effects. We are very vulnerable to these enhanced activities in the sun. The more we rely on these systems (electronics, computers) the more we will feel the effects of the suns tantrums.

But we still don’t understand all of the effects of space weather. No one can explain the effects on the climate, or why the disappearance of sun spots should cause an ice age. It may not matter, the small effects solar variations have on the planet have long since been drowned out by man made global warming. As the world warms up, the sun may yet prove an unlikely source of cooling. The greenhouse effect could be stopped by harnessing its heat.

Stirling Energy Systems, based in Arizona is the first commercial solar power station. Could these solar dishes be a type of direct descendents of stonehenge, etc. Although separated by 5000 years they all embody our desire to understand the sun. To be bathed in it’s light and to tap in to its awesome power.

When the sun dies in 5 billion years a small part of the outer arm of the milky way, our very own galaxy, will be a little bit darker.