A detailed explanation is available on this simple website or watch this 30 minute explanation on YouTube.
To understand modern climate change a knowledge of the natural cycle of ice ages and warm periods is a great help. Once the simple mechanics of how the system works is appreciated it is easier to see where we are going wrong and the likely consequences of our actions.
A detailed explanation is available on this simple website or watch this 30 minute explanation on YouTube.
In a 2C to 3C warmer world, more like the Pliocene epoch, what can we expect to happen to our trees?
For the last million years the Earth’s temperature has had a cyclical pattern of ice ages and warm periods (we are now in a warm time) and the cooler periods would have been 8C cooler. CO2 is a greenhouse gas that drives temperature change and during these cycles CO2 cycled through a range of 280 parts per million in a warm period down to 180 parts per million in an ice age. In the depths of an ice age the world would have had thick glaciers down to Scotland or New York and the sea level would have been 120 meters lower than today.
Our atmosphere now holds CO2 at a level of 400 parts per million and to get an idea of what the climate would be like we need to go back 2.5 million years or further to the Pliocene epoch as that was the last time we had CO2 at this level.
If you think that this scenario is improbable, travel to a place where the temperature is about 3C different from where you live, which would normally be about 1000 Klm (650miles) North or South, and look at the trees. They will be mostly different and they are suited to their region.
The huge pulse of CO2 we have put into the atmosphere is, in geological terms, so short that it is like being hit by a meteor. From 280 ppm to 400 ppm in one hundred years is unlike any natural event at all and we are headed for 450 ppm in the near future. The Earths atmospheric temperature has not caught up with the changes as 90% of the heat has gone into the oceans and although the ice is melting it takes time to melt a block of ice. Nevertheless the surface temperature has increased by 0.8C and is going up steadily so that we can expect to see some dramatic changes in our lifetime as the inertia in the system gathers speed.
The IPCC projections shown in the graph for CO2 emissions continuing at the current rate of ‘business as usual’ indicate a CO2 level of around 700 to 1000 ppm of CO2 at the end of the century with a temperature 2C higher and climbing steadily so using the Pliocene epoch as a model for our future climate is a realistic assumption.
The big action with climate change is in the oceans, but here we are looking at the land and plant life and using trees as an example, we can anticipate how they will fare in the new climate.
The trees of the Pliocene period were similar, but different, to the trees of today and were adapted to the climate that went with it. Those trees had taken hundreds of thousands of years to evolve to match those conditions. The trees we have today are adapted to a CO2 level of 280 PPM and a climate 0.8C cooler than todays and are rapidly going into conditions 2C warmer and with dramatically changed rainfall conditions of either drought or flood.
We know that trees like CO2 and will grow faster if they get more of it, but what is not so well known is that there are other elements that a tree needs to make use of this extra stimulus. One of these is nutrients and trees often grow in quite poor soil and if they grow too fast they will run out of food and will then starve. The second and most important element is water. With the extra CO2 come higher temperatures and a change in climate. The warmer climate causes the soil to dry more quickly and a change in weather pattern can lead to extended periods without rain and this will stress the tree and weaken it. At the same time, the change in climate can also lead to an increase in new diseases and insects which can damage the tree. In its weakened state the tree is overcome with disease and can die.
As trees die they become fuel for forest fires. To make the situation worse, the combination of a warmer climate and increased drought dries the forest out and the whole area becomes more susceptible to huge destructive fires.
A less known problem comes from the density of air in a warmer climate. For every 1C increase in temperature the atmosphere holds 8% more moisture and water is 800 times denser than air. The result is that a warm moist wind has a lot more destructive power than a drier wind of the same speed. The problem here is that trees are adapted to their region and have leaf canopies and root structures suitable for the original climatic conditions. If they have to deal with a storm more suited to a region thousands of miles away their root system will not hold and they will be blown over.
All round the world countries are reporting that species of trees are already suffering and dying in huge numbers and the situation can only get worse as the temperature increases in the future.
We all know that there is so much water locked up in the ice of Greenland and Antarctica that if it melted it will cause serious flooding. In all the large figures of sea level rise it should be remembered that just one metre rise will bring massive economic losses for every country with a shoreline.
There are two big ice sheet regions, Antarctica and Greenland. Antarctica is split in two with East and West and we can ignore East Antarctica which is so high and cold it is not melting yet. This leaves West Antarctica which has enough ice to raise sea levels 4.8 meters and Greenland which has enough ice to raise 7.5 meters, they are both completely different and both of them have melted completely in the distant past.
Greenland is a high rocky island which has ice on its surface that is two kilometres thick and has glacier tails that sit in the sea, Its vulnerability is that its surface melts in the summer and when it does so the dark blue water absorbs more of the sun’s heat than white ice and this warmer water melts into the ice and eventually makes a hole that will carry a whole lake of warm water into its interior.
Not much is known about where this warm water goes but the concern here is that the increasing number of holes in the ice and the amount of warm water in the interior are weakening the ice sheets core which will become rotten and vulnerable to catastrophic collapse. There are many elements to Greenland’s ill health, including the amount of soot on the surface that speeds melt and also the increasing speed of glaciers heading to the sea. All in all Greenland is not in good shape.
West Antarctica has a different set of problems in that it is a string of islands that are covered in a huge sheet of ice but much of this ice is sitting on the sea bed. The concern here is that the sea water is warming and washing around the bottom of the ice and melting it rapidly. Water has a thermal conductivity that is 24 times greater than air so it has a greater capacity to melt ice quickly and the ocean water is warming.
Two East Antarctica ice sheets have broken off and collapsed already but these were floating in the sea and did not add much to sea level rise but they did demonstrate the vulnerability of West Antarctica. The warmer water has been measured at melting 50 mm of ice a day which may not seem much if the ice is 1000 metres thick but it weakens the sheet and then storm waves can break the sheet which then collapses.
The problem in forecasting a sudden collapse is working out the mechanism of how it happens and then putting a timescale to it. There are precedents in the recent past when sea level rose at 10 mm a year compared with the current 3.6mm a year. At 10mm a year or 100 mm every ten years or one meter in 100 years we could see some serious consequences with inundation of major cities and infrastructure but a sudden ice sheet collapse could bring this foreword in an irregular timescale.
There was a piece posted on Climate Denial Crock which showed John Stewart of the Daily Show lampooning the House of Representatives Science, Space and Technology member Steve Stockman (Rep Tex) having trouble with the Earths wobble when questioning the Governments lead climate scientist. Why a politician who has declared that he does not understand science would question a scientist who is top of his field is a mystery but I thought it might be worth a quick explanation of why it is not considered in the models.
The Earth’s “wobble’ goes from 22.1 degrees when it is nearly upright to a maximum tilt of 24.5 degrees which for simplicity we will call 2.5 Degrees.
This action takes about 125,000 years which is from the depth of an ice age through a warm period and back to an ice age in a repetitive cycle.
This ‘wobble’ happens at the rate of 0.02 degrees every thousand years, or 1 degree every 50,000 years. It is quite a serious movement as during the whole cycle the world would cool 8C, glaciers of ice would be down to Scotland or New York and sea levels would drop 125meters.
Climate change forecasting concentrates on the next 100 years with real detail going into the next fifty or even less. With such a vast difference in timescale the climate modellers ignore the tilt action although they are well aware of it's presence.
We should be headed for an ice age but the huge pulse of CO2 we have pumped into the atmosphere has changed our destiny. We have to stop burning fossil fuels which was the real reason the Texas Representative was displaying his ignorance.
Click here for a more detailed explanation.
A few weeks ago we had a steam pipe burst at our local geothermal plant and it took some time to get it fixed because nobody was on duty at the plant.
Nobody was on duty!
The geothermal generators were supplying us with electricity and nobody was there.
Power stations powered by coal are very powerful and a relatively large one running at its normal 50% of rated capacity would be burning about 5000 tons of coal a day. If you take the operating costs over twenty years with the fuel bill, engineers servicing boilers and general maintenance costs its an expensive beast to run.
The coal consumption of 5000 tons a day is producing 15,000 tons of CO2 and other pollutants a day and despite 30 years of talking about carbon capture it has not been achieved. The simple reason is that it is far too expensive to achieve and coal is only cheap as long as you vent the pollution to the atmosphere for free.
Another cost of burning coal is the health of the miners.
Nobody goes into mining as a lifestyle choice as it is a dirty, dangerous, health destroying occupation and much of the heath costs are taken by the state and paid for out of taxes.
Wind generation, hydro, geothermal and solar all have their energy supplied by nature so that over a few years, when the capital construction cost are covered the cost of the electricity tumbles.
If all the miners were re-employed erecting and installing wind generators and solar panels the miners would have a heathier and more fulfilling life and we would have cheaper electricity.
CO2 in the atmosphere has climbed from a normal maximum of 280 parts per million to the current 400 ppm. A level we have not seen on this planet for 3.5 million years. In that period there was a completely different environment with temperatures 3C warmer, sea levels 12 metres higher and higher levels of ocean acidity in the oceans. A world in which today's plants and animals were not designed to live.
We need to stop burning coal urgently and build up out renewable electricity capacity and ultimately convert our transport to electricity.
The first point to appreciate is that, of all the extra heat absorbed by the planet due to global warming, 93% goes into the oceans 5% goes into melting ice and only 2% goes into warming the atmosphere. This means that the oceans have an overwhelming effect on the surface temperature of the atmosphere.
The next part of the puzzle is the big difference between the Arctic and the Antarctic. The Arctic is an ocean surrounded by land and the Antarctic is a continent of land surrounded by sea. Another difference is that the Arctic is all at sea level and the altitude of the Antarctic land (or ice) is 3000 metres (10,000 feet) and is therefore about 20 centigrade colder due to its height.
Even allowing for these differences the Arctic is warming faster and this is to do with the geographic layout and the capacity of water to absorb heat.
The Arctic is a closed ocean and does not have strong currents or big storms (these things are all relative).
The Antarctic continent by comparison has an uninterrupted flow of strong winds always blowing in the same direction and blowing 365 days a year right round the World. This powerful, constant wind pushes the sea along to form a strong current which is one of the power sources that drive the ocean conveyor, to spread heat around the world and because it is consistent the current reaches into the deepest parts of the ocean where the coldest water lies.
The Southern Ocean is not consistently deep and has several shallow points. The most noticeable is between South America and West Antarctica but another is between the French Southern Ocean Lands and the Antarctic and another between New Zealand and Antarctica. These shallow areas (again it’s all relative) form turnover points where the cold deep water is driven to the surface where it can mix with the atmosphere and perform a heat exchange. The constant storms in the whole region also constantly churn the surface of this cold water and suck heat from the atmosphere and the combination of all these actions keeps the atmospheric temperature from rising to the levels seen in the Arctic.
This heat has not gone away it is just being redistributed and will come out later to force atmospheric temperatures up with a speed reminiscent to the period between 1970 and 2000.
In the last eight weeks we have had three rain events of around 200 mm and in two of them there have been bursts when the downfall was in the region of 50 mm an hour. We get quite a bit of rain in the winter but this was bordering on the exceptional.
I am part of an environmental group which is improving the quality of water in the Bay of Islands in order to restore the estuary breeding grounds for fish. Erosion of the banks of rivers and streams blankets the normally fertile estuaries with mud and destroys the eco system in which juvenile fish thrive. Without fish nurseries we will not have fish.
We had just planted a section of a stream to restore vegetation to the banks so that the roots hold the soil together to resist erosion when we had the first 200 mm event. This washed a lot of our recent planting out of the ground. We assembled another team of volunteers and replanted the stream edge. Then we had the second flood event which was bigger and did more damage than the first. We were running low on plants by this time but we recovered what we could and planted more trees when we had the third event. The last one did not have a rain burst and so it did not flood to the same extent but it certainly made us think. It also confirmed the value of our work as we could see the amount of soil lost in the small section on which we were working.
On a personal level the gutters on my house, which is thirty years old, were not able to cope with the downpour and overflowed leading to water coming into the house. There are just not enough downpipes to the gutters to drain away rain which falls at the rate of 50 mm an hour. So I am in the process of fitting three new downpipes to cope with future rain events.
Are these events becoming more common. Simple science tells us that for every degree in temperature rise the atmosphere can hold 8% more moisture. New Zealand has had a temperature rise of 0.9 Centigrade and so every rain event has an element of climate change in it.
As Kevin Trenberth said. "The answer to the oft-asked question of whether an event is caused by climate change is that it is the wrong question. All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be”.
I study climate change so I am looking for evidence but am I putting two and two together and making five, am I getting paranoid?
Methane is a very powerful greenhouse gas and even though in time it will wash out of the atmosphere it is 72 times more powerful than CO2 over twenty years so it needs to be considered.
Methane hydrates are essentially frozen methane held on the seabed by a combination of low temperatures and deep water pressure. If the water warms, the methane can be released and bubble to the surface and there are vast quantities held there, sufficient to change the climate rapidly, so it is of considerable concern.
Previous scientific analysis has said that the chances of this happening are remote and up to now there has been little research in the area.
In an interview between Nazeeth Ahmed of the Guardian and Prof Peter Wadhams, co-author of the Nature study and head of Polar ocean physics at Cambridge University it was explained that there is a completely new situation.
In a shortened version, the East Siberian continental shelf is very shallow and is normally frozen over and very cold and so it has held the methane hydrates safely on the sea bed.
The new situation is that the sea ice has melted for long periods in the summer and raised the temperature 7C and this is sufficient to melt the methane and release it to the surface.
Professor Peter Wadhams is one of the few scientists to work in the field on the Siberian sea and like many scientists who work on the ice he is considerably more concerned than the rest of the scientific community.
Something to watch closely and no doubt there will be more research ships in the region next summer.
There have been several articles about the pause in global warming and these have been instigated by some new research which shows that the heat is going into the Atlantic. In fact it said that the Pacific Ocean could not absorb the sufficient heat to account for the pause. The researchers looked at the records from the Argo floats and found that the extra heat was going into the Atlantic.
93% of the world’s heat is stored in the oceans so it has an enormous effect on the atmospheric surface temperature anyway and our records of the oceans are abysmal. The Argo floats are doing great stuff but they have only been in operation ten years and only record the top 2000 metres, which is not much to go on.
A quick look at the NASA temperature records since 1880 shows that there have been two previous pauses and the last one lasted thirty years so we have a bit to go yet.
The pauses are caused by heat going into the ocean deeps from the Gulf Stream, Southern ocean and Alaskan current and coming out decades later.
In the meantime the heat and the ocean acidity that travels with it are doing untold damage in our oceans.
We are not going to run out of oil in the near future but all is not well in the oil world. It is decades now since oilmen have found more oil than we are consuming and increasingly difficult exploration has led to very deep ocean wells, Arctic exploration and fracking for tight oil. All are extremely expensive. Fracking has helped the USA to boost its oil production substantially and consumption savings in other parts of the world has offset the rising demand in emerging economies such as China and India.
What has changed is the high cost of exploration and extraction for very meagre returns. The oil companies have been selling assets and taking on more debt to fund their operations and the breakeven price of new oil has moved from $40 dollars a barrel to around $100 a barrel and some at $120 a barrel.
At the moment the price of oil is hovering around $100 but if ever there was a time for countries to be investing in electrical transport it is now. Many countries, including New Zealand have almost no other type of transport power except oil and their economies will be hard hit with a big price rise.
Oil is a diminishing resource with a volatile price and it would be prudent to have alternative transport systems to insure the economy against sudden price hikes.