20. TIME for YOU to DECIDE about 350
Time to decide about climate change and 350. Here are the main arguments.
The basic disagreements.
Those who say we should do nothing about climate change.
There are those who do NOT accept that climate change is happening.
There are those who accept that it IS happening but claim that it is entirely due to natural processes -
and therefore we have nothing to fear because the climate will return to 20th century conditions.
There are those who accept that it IS happening, it IS the result of burning fossil fuels,
the climate will NOT return to 20th century conditions BUT there will be no serious consequences.
Those who say we should do something about climate change.
There is almost complete agreement among climate scientists that burning fossil fuels has caused more climate change
than natural processes over the past few decades or for much longer.
They say that the rate of burning fossil fuels has been increasing steadily for decades
and that if this continues the climate changes will be very serious indeed in the decades ahead.
They say that the effects of burning fossil fuels NOW does not show its real impact until decades – many centuries – later.
They also warn that climate change is close to ‘tipping points’ where it becomes too late to halt the process
(eg if the polar ice sheets melt beyond a certain stage the melting cannot be reversed and sea levels rise until they submerge cities).
Decision Time
The choice is obvious. If the climate scientists are right we need to take decisive action now.
That means reducing the use of fossil fuels very substantially and very quickly.
That will derupt traditional economic practices and affect our lifestyles.
So it is not surprising that many people don’t want to take climate change seriously
BUT that could be very serious for our children and grandchildren if the climate scentists are right.
So a responsible decision could be taken NOW without further questioning on the basis
that the climate scientists have got the expertise and overall must be sure of their conclusions.
But, if you want to question the scientists expertise before deciding.
Can you guess if the science is right without understanding it?-There is a simple test that you can use to guess whether the climate scientists might be right in their overall conclusions
or their critics might be right in rejecting those overall conclusions.
You don’t need to understand the climate science for this but you do need to understand how science works.
Scientists constantly scrutinize eash other’s work, trying to find more reliable answers to all the detailed processes they study.
So the work of climate scientists is very thoroughly tested by other climate scientists or anyone else who can spot a flaw.
Mistakes are often found but over decades and centuries some findings become very thoroughly tested.
Now the critics of the climate scientists’ overall conclusions have NOT presented evidence to support their claims.
If they had, scientists of all kinds would srutinize this evidence because, if it turned out to be convincing it would
open up new investigations – something as big as this could earn a Nobel prize.
What the critics have done is NOT a scientific challenge to the overall conclusions of climate scientists, it is showing up
occasional errors in huge quantities of data and making claims in the media that they are not required to substantiate.
So you might want to decide on the basis that climate scientists as a whole have rigorous science to support their overall conclusions
whereas their critics have no case unless they can put up equally rigorous scientific evidence.
However, before you decide, you may want to know more about the evidence the climate scientists have tested thoroughly.
What kind of scientific evidence is the basis of the climate scientists’ overall conclusions?-You can get a very good understanding without going into details.
Start with coal, oil, gas. Across the world, we have burned huge quantities and we are burning more and more.
When these burn they turn into carbon dioxide gas. Some is absorbed in the oceans causing damage.
But more than half of this gas goes into the upper atmosphere and stays there for hundreds of years.
Sun light comes down through the upper atmosphere and heats our planet, but almost all of the heat is reflected back into space.
For thousands of years the balance between sun’s heat in and the reflected heat out has been equal
and has kept the world’s temperature about right for us. That stable temperature has now been changing.
The carbon dioxide gas we have been putting into the upper atmosphere has upsets that energy balance.
With a bit more heat is coming in than is reflected out, over many years the earth has got warmer and this has already affected climates around the world.
In some parts of the world climate change is already having serious effects.
Wherever we live, these serious effects will cause major problems in the next few decades.
If we do nothing now it will be too late to stop climate changes that will make our earth a far worse place for our children and grandchildren.
They will blame us for being so stupid and selfish when we could stop the climate changes in time.
This simple account may be all you need to know to make a responsible decision
but it is such a big decision you may need to know more to make the science believable.
More -
If you want to read all of the arguments against climate change and you want to see an answer to each argument based on good science
that show convincingly that the arguments against claimte change are weak, wrong, and not backed by good science
then go to Skeptical Science website – they are all there and you can get them on an iphone app
Go to: http://www.skepticalscience.com/-
Climate science – how can we believe such huge conclusions?The problem is that what we understand best is our experience in a particular part of the world and with a short time scale. To believe what the climate scientists are telling us we have to expand our understanding to the whole planet we live on, and a time scale that goes back hundreds of millions of years. The climate scientists have instruments spanning every part of our world, on land and in the oceans and satellites measuring many changes of complex chemicals, changes in the sun’s intensity etc. They have also probed back in time through analysis of ice cores taken down to levels from 800,000 years ago. These give information about how the world’s climate has changes and the amounts of key chemicals involved. The detail of the climate scientists’ understanding has been built up over centuries and so they have a reliable basic understanding of what has happened in the past and what is happening due to carbon emissions now. At this stage they are working to clarify the complex details that require measurement of the processes involved. For example, for many decades they have used measurements to prove that the huge ice sheets in Antarctica and Greenland are shrinking overall but the measurements to show how the ice is lost are much more difficult to obtain – eg. recent work suggests that melting from below has more effect than melting at the surface of the ice and this may be why the process is accelerating. What is also thoroughly understood is that once the melting of the ice sheets reaches a certain stage, the process of acceleration can’t be stopped and that means all over the world sea levels will keep rising until vast numbers of people are displaced from coastal cities etc.
It is not surprising if people without the experience of climate scientists find it unbelievable that the world as we know it could be catastrophically changed within the lives of our children or grandchildren. But this is not science fiction – our world has only had the stability that we think is normal for less than 12,000 years. The evidence is undeniable that it has gone through the kinds of changes the climate scientists warn us about many times before – and it is carbon dioxide in the upper atmosphere that produced the global warming phases.
So just try this and if it makes sense that is all you need to know to make a rational decision.
From 1957 we have an accurate, day by day measurement of the carbon dioxide from the top of a mountain in the Pacific Ocean. Over the past 800,000 years the level was never above 300 ppm and since 1957 it has climbed from 312 ppm to 387 ppm. The most respected climate scientist James Hansen who first spoke out about this danger, estimates that we have to stop the carbon dioxide level rising and bring it down to 350 ppm or less to avoid unbearable global changes. This means completely phasing out the use of coal and other measures. That is an enormous task and we have to do it across the world in the next few years. It will affect everyone although more people will benefit from the changes than suffer from them. It is the lavish, wasteful lifestyles that will have to end but a better, healthier society will emerge. Perhaps the decision is now obvious but the implications are too much to cope with – so many people just deny it all. It won’t go away because we want it to. Be brave, be responsible. For your children’s sake, face up to it. 350 now has a meaning for us all.
If you need to be convinced by reading the climate science – that is a very good way of getting a grip on the reality.-
How do you find out about 350? The best book by far is the Dec 2009 ‘Storms of my Grandchildren’ by James Hansen, the most important climate scientist.
This is really two books intertwined – one is a very readable and important account of James Hansen’s struggles with authorities who tried to censure his work – the other is his very systematic attempt to lead you through a simplified understanding of the basic climate science that leads to his conclusion that we have to get carbon dioxide down to 350 ppm. he simplifies the science very skilfully but it is still a great deal of information to work through and grasp so he conveniently shows you where you can skip the details. If your want a much shorter summary of the science try Tim Flannery’s book ‘The Weather Makers’.
Also for James Hansen’s website Go to: http://www.columbia.edu/~jeh1/
And for the 350 Campaign Go to: http://www.columbia.edu/~jeh1/
Or from the Welcome page of this website click the 350.org button.
CONCLUSION -
If you understand the crises climate change is already causing in parts of our world and how much worse these will become, spreading to every corner of the planet if we continue as we are, then there is only one sane response-we must all, the whole population of the planet, do whatever it takes to stop worsening climate change. Nothing less makes any sense. It will be a huge achievement but it can and must be done.