Sunday, 26 April 2015

Climate change: Richard Betts and the climate debate

Last month's Climate Week in Sidmouth
Futures Forum: Climate Week in Sidmouth: Mon 2nd to Sat 7th March
saw Professor Richard Betts of the Met Office and University of Exeter talk about numbers:
Futures Forum: Climate Week in Sidmouth ... "The 2 degree limit - dumbing down, or useful approximation?" ... Professor Richard Betts of the Met Office ... Tuesday 3rd March at 3pm

Prof Betts looked at how useful it is to talk in terms of statistics. Here he is looking at 4 degrees:

Richard Betts -- Impact of 4 °C rise in global average temperature on drought - YouTube

Prof Betts is at the centre of communicating the science:

Climate consensus: scientists and sceptics suspend hostilities
Twitter adversaries meet over dinner to discuss the climate debate, and why everyone hates each other so much, reports RTCC

Sophie Yeo Friday 3 October 2014

Twelve scientists and sceptics have met privately to discuss how to suck the venom out of the climate change debate.
It was one of science’s strangest social events to date.
Some of the best known names in the climate debate – including Mail on Sunday journalist David Rose, blogger Anthony Watts, and Met Office scientist Richard Betts – shared salmon and civilities at a dinner party last month.
Hosted by the sceptical scientist Nicholas Lewis at his house in Bath in September, the group discussed their similarities, differences, and how they might calm the debate that rages across the pathologically provocative medium of Twitter.
“Both sides are really fed up with the outrageous alarmists who are not representing science properly. Both don’t like those who shout about it and call people names and take a polarised point of view,” says David Whitehouse from the sceptic thinktank The Global Warming Policy Foundation.
The idea that there is some wiggle room when it comes to the facts of climate science is not always a popular one. The scientific consensus has already spelled out the catastrophic implications of delaying action on climate change, so fussing around uncertainties can be perceived as unhelpful.
Yet, when it comes to details, the scientists are as willing to admit it as the sceptics: the science is not settled – not fully – and the insults slung around online only hinder the process of rational scientific debate.

Climate consensus: scientists and sceptics suspend hostilities | Environment | The Guardian

Prof Betts is part of the scientific hub centred around the University and the Met Office:
Westcountry's dynamic dozen face off against climate change | Western Morning News

And he often provides comment - as in this recent observation on tropical cyclones:

Climate change aggravating cyclone damage, scientists say
Rising sea levels making island nations such as Vanuatu more vulnerable to storms and amplifies the impact of tropical cyclones

Karl Mathiesen Monday 16 March 2015 

Professor Richard Betts, head of climate impacts research at the Met Office Hadley Centre, said the human contribution to sea level rise over the past 100 years was well documented and makes island nations more vulnerable to storms and particularly storm surge.
“When cyclones and other storms occur, there is already a greater risk of coastal flooding because the background sea level has risen, largely due to human-induced global warming. How much more flooding has occurred due to human action is unclear, but ongoing sea level rise can be expected to further increase this risk unless coastal protection can be improved.”

Climate change aggravating cyclone damage, scientists say | Environment | The Guardian

Below are some of the main points from his talk given during Climate Week in Sidmouth:


> Ice caps are melting at an increasing rate:

National Geographic recently created a series of maps similar to Mr Vargic¿s, demonstrating the catastrophic effect Earth¿s ice could cause if it melted and flowed into the oceans and seas. If these ice sheets melted, the rest of the world would be affected. In Europe, pictured, cities including London and Venice would be lost underwater, as would the whole of the Netherlands and most of Denmark. It would also cause the Mediterranean to expand and swell the Black and Caspian Seas
Would YOU be underwater if the polar caps melted? Map reveals what our planet would look like if sea levels rose by 260ft | Daily Mail Online

> Dozens of species are being lost every day:

The Extinction Crisis

> Disruption in the weather is providing either too little or too much rain:

Will Drought and Climate Change Kill the Winter Olympics?
Will Drought and Climate Change Kill the Winter Olympics? | VICE Sports
Mediterranean dreams, climate realities | openDemocracy
Sydney weather: driving rain, damaging winds to batter NSW for second day

> Increased CO2 emissions are producing acidification of the oceans:

Photo: Fish swimming over coral
Ocean Acidification -- National Geographic
Coral Reefs and Climate Change - How does climate change affect coral reefs - Teach Ocean Science
Ocean acidification: global warming's evil twin
Emissions of CO2 driving rapid oceans 'acid trip' - BBC News

> Disease and pests are spreading as a result of climate change:

California Agriculture Online
Global issues - Global Food Security

> The impact on human populations is difficult to predict:

Management of plant pests and diseases in eastern and central africa

> There will greater impact on weather systems - and it is not clear how much is 'science fiction':

The Day After Tomorrow - Official® Trailer [HD] - YouTube
Climate Change: Day After Tomorrow New Ice Age Scenario Unlikely - But Not Ruled Out
Shock report claims 100m people to die and economic growth to drop by 3.2% by 2030 if climate change is ignored | Daily Mail Online

> The atmosphere has now reached 400 ppm CO2:

Panoramic view of the Mauna Loa Observatory, Hilo, Hawaii.
Climate Milestone: Earth's CO2 Level Nears 400 ppm - National Geographic
400 PPM: Carbon Dioxide in the Atmosphere Reaches Prehistoric Levels | Observations, Scientific American Blog Network
Climate Change: Vital Signs of the Planet: NASA scientists react to 400 ppm carbon milestone


How useful and reliable is the 2 degree rise in temperature?

> It points to the 'carbon cycle feedback':

Carbon Cycle Feedbacks
As we saw earlier in the course, the airborne fraction of CO2 in the atmosphere has increased by only half as much as it should have given the emissions we have added through fossil fuel burning and deforestation. We know that CO2 must be going somewhere.

Annual change in atmospheric CO2 concentrations.
Credit: Mann and Kump, Dire Predictions: Understanding Global Warming (DK, 2008)

Indeed, it is being absorbed by various reservoirs that exist within the global carbon cycle. As we saw earlier in the course, only 55% of the emitted carbon has shown up in the atmosphere, while roughly 30-35% appears to be going into the oceans, and 15-20% into the terrestrial biosphere.

Global carbon cycle.[Enlarge]
Credit: Mann and Kump, Dire Predictions: Understanding Global Warming (DK, 2008)

The problem is that this pattern of behavior may not continue. There is no guarantee that the ocean and terrestrial biosphere will continue to be able to absorb this same fraction of carbon emissions as time goes on, and that leads us into a discussion of so-called carbon cycle feedbacks.
Carbon Cycle Feedbacks | METEO 469: From Meteorology to Mitigation: Understanding Global Warming

> 2 degrees is a critical number:

2 degrees Celsius A critical number for climate change - YouTube

(CNN)We're 2 degrees from a different world.
April 24 2015
Humans never have lived on a planet that's 2 degrees Celsius (3.6 Fahrenheit) warmer than it was before we started burning fossil fuels, in the late 1800s, and climate experts say we risk fundamentally changing life on this planet if we do cross that 2-degree mark.
"This is gambling with the planet," said Gernot Wagner, the lead senior economist at the Environmental Defense Fund and co-author of the book "Climate Shock."
Think super droughts, rising seas and mass extinctions.
Yet for all of its importance, I don't think the 2-degree threshold is as famous as it should be. I've heard it referred to as the "north star" for climate negotiations. Meaning: This one little number carries huge importance as a way to focus the world's attention.

Climate change: 7 questions on 2 degrees (Opinion) - CNN.com
Climate change: 'Two degrees' may decide the future - CNN.com

> 2 degrees serves to focus on the dangers of a 'tipping point':
Two degrees warmer may be past the tipping point | University Post
Tipping point (climatology) - Wikipedia, the free encyclopedia
The Tipping Points | TVO
Global warming: passing the 'tipping point' - Environment - The Independent
Paris Talks Won't Limit Global Warming to Less Than 2 Degrees Celsius - Scientific American
A degree by degree explanation of what will happen when the earth warms

> 2 degrees is the internationally-agreed target for limiting global warming

What happens if we overshoot the two degree target for limiting global warming?
10 Dec 2014, 12:30 Roz Pidcock

Two degrees is the internationally-agreed target for limiting global warming, and has a long history in climate policy circles. Ambition that we can still achieve it is running high as climate negotiators gather in Lima to lay the groundwork for a potential global deal in 2015.
But against this optimistic backdrop, greenhouse gas emissions have continued to rise. With each passing year the scale of the task looms ever larger. There are very real questions about whether or not the world will be able to stay below the two degree limit.
So what happens if we fail to meet the two degree target? What would it mean to resign ourselves to a post-two degree world? And if not two degrees, then what?
As temperatures rise, so do the risks
Two degrees above pre-industrial temperature has been agreed by countries as an appropriate threshold beyond which climate change risks become unacceptably high.
Global temperature has risen 0.85 degrees Celsius since 1880, according to the latest report from the Intergovernmental Panel on Climate Change (IPCC).
We could be due another couple of tenths on top of that as past emissions take a decade or so to reach their full effect warming. Together with current and expected emissions we're essentially already committed to about one degree of warming, scientists estimate.

Observed global mean temperature from 1850 to 2012, relative to the 1961-1990 average. Coloured lines represent three different datasets. Top panel shows yearly averages, bottom shows decadal averages. Source: IPCC 5th Assessment Report
While the international community uses two degrees as the rule-of-thumb threshold for "dangerous" warming, some climate impacts are already locked-in, particularly for low-lying and island nations. Professor Anders Levermann from the Potsdam Institute for Climate Change Research tells us:
"At one degree we are already experiencing damages. Sea level rise in the long term ... is somewhere in the vicinity of two metres. That puts cities like New York, Calcutta and Shanghai in difficult positions, and they need to protect themselves."
Rising temperatures have consequences for food and water security, infrastructure, ecosystems, health and the risk of conflict, says the IPCC. And the higher the temperature, the greater the risk those climate change impacts will be serious and damaging.

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