A wonderful resource Jonathan has put together.
Review, and ponder!
A blog alerting all citizens living in coastal areas of the need to move our civilization above the highest level the ocean will rise to once all the ice sheets are gone, in the hope that we will take precautionary action; prepare for the worst while wishing for the best.
1 The 100 Metre Line is a blog enabling people to consider and present the issues raised by the sea level rise component of climate change.
2 Why The 100 Metre Line? See the section at the bottom of this page.
3 What is the scientific basis for The 100 Metre Line? See the section at the bottom of this page.
4 So? OK. The 100 Metre Line is intended to give you the tools you need to present a major signal about our climate-changed future in a way that can be understood by ordinary people, and by policy-makers and elected representatives.
5 The main things you will find here are:
A. Information about how high the ocean will be by various dates in the future.
B. Suggestions about how you can present this information to the public.
C. An action plan suggesting some ways you can use The 100 Metre Line to support your 350.com activities.
D. A moderated blog where I present postings by people and organisations about how they are using The 100 Metre Line for their 350 activities and for other landmark presentations of the sea level rise and climate change issue.
6 It is difficult to show the effect of climate changes such as temperature rise, increased flooding or desertification at specific locations and times. We can paint word-pictures of such futures, but these descriptions do not resonate in hearts and minds of people to the extent that they may consider a need for action to address the issues so described.
I believe that the most effective, tangible and ‘real’ indicator of the changes that are approaching is an indication of the date and level the ocean will reach among the communities we live in. The erection of temporary or permanent markers of likely sea levels at specific iconic locations nationally and at strategic sites around the world will provide citizens with a clear indication that change is coming, and will send an unambiguous message to policy makers and elected representatives about the need to attend to these most urgent matters.
If you live below the 100 metre line, then make sure you have a High Tide maker on your front lawn. It may not help your property values, but it will make the neighbours think!!!!
7. Is it 'accurate'? Nope. This is a best-guess at future sea levels. The only hard facts we have are that the sea is rising. It will rise by more than 2 metres and quite conceivably by up to 5 metres by 2100. Sometime later (a thousand years or so) all the ice will be melted and the coasts of the world will start to settle down again. I've just joined the dots of a sine-like curve connecting those points. Prove me wrong!!!
8. Who am I? Nigel Williams. Auckland. New Zealand. An ordinary citizen.
This is a very brief overview of the state of knowledge relating to climate change and hence to the expected degree of sea level rise.
You must do your own study and arrive at your own conclusions so that you can defend your stance to those who simply do not understand, and to those who would like to learn more. We cannot turn around those who do not want to hear or believe – that is for their conscience. We must work with the people in the middle ground and present them with clear and honest information that they in turn can use to make personal and political decisions about the futures of their own families.
The IPCC and many peer-reviewed papers have been and continue to give us clear warnings that we must reduce the forcings on the global climate or we will reach a point where change will become dangerous for all humanity.
The climate changes most evident to scientific observers are increases in greenhouse gases and the consequent increase in the average surface temperature of the globe. A direct effect of these temperature increases is already evidenced in increased rate of melt of snow fields, glaciers and ice sheets around the world. The scientific literature tells us that unless we reduce global temperatures this melting will continue until the ice is gone.
Global Warming Twenty Years Later: Tipping Points Near: James Hansen
“…if emissions follow a business-as-usual scenario, sea level rise of at least two meters is likely this century. Hundreds of millions of people would become refugees. No stable shoreline would be reestablished in any time frame that humanity can conceive.”
“…The disturbing conclusion, documented in a paper2 I have written with several of the world’s leading climate experts, is that the safe level of atmospheric carbon dioxide is no more than 350 ppm (parts per million) and it may be less. Carbon dioxide amount is already 385 ppm and rising about 2 ppm per year. Stunning corollary: the oft-stated goal to keep global warming less than two degrees Celsius (3.6 degrees Fahrenheit) is a recipe for global disaster, not salvation.”
And in May 2009:
"The new projections, published this month in the American Meteorological Society's Journal of Climate, indicate a median probability of surface warming of 5.2 degrees Celsius by 2100, with a 90% probability range of 3.5 to 7.4 degrees. This can be compared to a median projected increase in the 2003 study of just 2.4 degrees. "
So: In May 2009 MIT scientists running a sophisticated and well-respected climate model tell us that there is a median probability that the Earth will be 5.2 degrees Celsius warmer by 2100.
And: In 2008 Hansen stated that even 2 degrees Celsius of global warming ‘…is a recipe for global disaster…’, and …if emissions follow a business-as-usual scenario, sea level rise of at least two meters is likely this century. … … No stable shoreline would be reestablished in any time frame that humanity can conceive.”
Thus: Given our practical inability to return CO2 levels below 350 ppm, and the new predictions of global temperatures by 2100, global sea level rise is both inevitable and unstoppable by mankind.
I don’t propose to offer any more ‘scientific’ information here. Please continue your education.
See the section above giving an estimate of the global sea level rise profile reasonably expected over the period from today until the ice is all gone and coastlines begin to stablise again: Dates and Corresponding Sea Levels.