IPCC have made some mistakes
Five years ago, the last report of the Intergovernmental Panel on Climate Change (IPCC) painted a gloomy picture of our planet’s future. Here are 6 points that show they have underestimated the magnitude of the problem.
1- The Arctic is melting faster than predicted.
In 2007, the IPCC consensus was that the Arctic would not be ice free in summer until the end of the century. But climate change models have clearly underestimated the pace of change. If current trends are a reliable guide, we will start seeing ice free Arctic summers within a decade.
The knock on effect of an ice free Arctic will be a rapid Arctic warming, because dark oceans absorb more heat than reflective white snow and ice. A warming Arctic will accelerate Greenland melting, will lead to a release of CO2 and methane from permafrost and result in more extreme Northern Hemisphere weather.
2- Extreme weather is getting more extreme.
Even at the time of the last IPCC report in 2007, the trends for extreme heat, droughts and intense rainfall were clearly upward.
Not only are these trends continuing, but the weather is becoming more extreme than was predicted.
3- Food production is taking a hit.
In 2007 the IPCC predicted that if global temperatures rose 1.5°C or more above pre-industrial levels, greater warmth and higher CO2 would increase crop yields, at least in temperate regions. Only warming of greater than 3.5°C was expected to lead to a big drop in food production.
Unfortunately climate change is already having an adverse effect, even though the world has warmed just 0.8 degrees. Average yields are now more than 1 per cent lower than they would have been with no warming. The negative effects of climate change are significantly outweighing the positive ones.
4- Sea levels are rising faster than expected.
The 2007 IPPC report assumed that the Greenland and Antarctic ice sheets would contribute just 0.3mm a year to sea-level rise, with the bulk of sea-level rise coming from thermal expansion.
Satellite measurements have since shown that the two ice sheets are already losing enough ice to raise sea level by 1.3mm a year, and climbing.
Most glaciologists now think that sea level will rise by a metre by 2100. This is higher than the IPCC’s worst case projections.
5- Greenhouse gas levels will keep rising even if our emissions stop.
The 2007 IPCC report made no attempt to predict how much carbon locked away in permafrost and in methane hydrates in the seabed might also be released.
This year, researchers from the University of Victoria in British Columbia concluded that carbon released from melting permafrost will lead to an EXTRA warming of as much as 1°C by 2100.
Even if all human emissions stopped, CO2 levels would continue to rise as permafrost melted, leading to further warming and carbon releases.
6- We’re emitting more than ever.
Global emissions are rising at a rate of about 3% per year which puts us at the top of the IPCC?s worst-case emissions scenario. We are on a path that the 2007 IPCC report concluded would most probably lead to a 4°C rise in temperature by 2100? way above the 2°C level it declared we should avoid at all costs.
Best estimates are now for a warming of between 5°C and 6°C by 2100, given the current emission trajectory.
Matthew Nott
Climate Change is bad for your health
The health impacts of unmitigated climate change are going to be enormous.
In a warming world the risk of heat related deaths will increase. That seems crazy in this day and age when we can sit inside in air-conditioned comfort and wait for a heat wave to pass. The problem is when it’s really hot everyone will have their air-conditioners on, which increases the risk of black-outs. A black-out is life threatening in the middle of a heat wave.
Changing rainfall patterns in a warming world will significantly alter the distribution of malaria which will be put enormous pressure on health services, particularly in third world countries.Other vector born diseases such as Dengue fever might start to impact us in SE NSW.
Deaths from extreme weather events will be an increasingly important issue. Wild fires, flooding, typhoons and cyclones are already increasing in severity. It is likely the world will be 2 degrees warmer within many people?s lifetimes, so extreme weather events are going to become part of our day to day existence.
The biggest problem will be psychological.
In our part of the world, psychological problems will relate to rising sea levels and changing rainfall patterns.
Whilst the science of sea level rise is unequivocal, many Australians (and some politicians) remain unconcerned, mainly because a 3mm annual sea level rise is imperceptible to individual observation. The level of concern and awareness will rise over the next few decades and when that happens the value of coastal real estate is going to plummet. Failing coastal real estate is going to create massive social pressure and issues related to depression and anxiety.
A warming world will change rainfall patterns which is going to put pressure on farming practices in south east Australia. Depression within the farming community after prolonged drought will be a major challenge. Farmers are going to be forced to adapt quickly to changing conditions.
The health impacts of climate change are going to affect us all.
Matthew Nott
No Time To Waste
Carbon dioxide emissions into the atmosphere are set to reach 36 billion tonnes of carbon dioxide this year, which is 58 per cent above 1990. Growth rates of about 3 per cent per year have been the norm since the beginning of the 2000s, except for a small drop in emissions during the Global Financial Crisis in 2009.
It is clear that limiting global warming to 2 degrees Celsius above pre-industrial levels requires an immediate, large, and sustained global mitigation effort.
Emissions trends over the past ten years are tracking consistently towards a 4 to 6 degrees Celsius warming over pre-industrial times by the end of this century.
Although emissions from the European Union have been declining for almost two decades, and more recently for the US as well, emissions growth in emerging economies such as China and India were 10 per cent and 8 per cent in 2011, respectively. It is difficult to envision how such high rates can be curbed any time soon, with China?s urbanisation not peaking until 2030, and India with half a billion people below the poverty line requiring increased per capita energy consumption to achieve desirable standards of life quality.
However, there are examples in the recent historical records that show rapid transformation of energy systems for some countries, which have led to emissions reduction of 2-4 per cent, consistent with the mitigation rates required to meet the 2 degrees Celsius target.
For instance, the oil crisis of 1973 led to a decrease in the share of fossil fuels (oil shifted to nuclear) for energy production in Belgium, France, and Sweden, with emission reductions of 4-5 per cent per year sustained over ten or more years. A continuous shift to natural gas, partially substituting coal and oil, led to sustained mitigation rates of 1-2 per cent per year in the UK in the 1970s and again in the 2000s, 2 per cent per year in Denmark in the 1990-2000s, and 1.4 per cent per year since 2005 in the USA.
These examples show that for individual countries, it has been technically and economically feasible to achieve rapid transformation of energy systems. The challenge is whether these examples for single countries, lasting each no more than a decade, can be applied globally and sustained for many decades.
Pep Canadell is Global Carbon project Executive Director at CSIRO.
Permafrost Melting Fast
New science suggests that global plans to hold climate change to an average 2 degree temperature rise this century are likely to be difficult.
Arctic permafrost is melting, and its happening much more quickly than was previously thought possible.
Billions of tonnes of carbon are locked up in permafrost, and as it melts methane is released into the atmosphere. Methane is a much more powerful green-house gas than CO2.
Human induced climate change is causing the planet to warm, which is melting permafrost and releasing methane, which is accelerating climate change.
It is a positive feedback loop which has the potential to greatly accelerate global warming, and is the sort of process that can lead to tipping points.
Until very recently permafrost was thought to have been melting too slowly to make a meaningful difference to global temperatures this century.
NASA’s Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) has been monitoring Arctic methane and CO2 levels and has found that large-scale thawing of permafrost is already well underway.
The rate of melt is “deeply concerning”, said Andy Pitman, the director of Australia’s Centre of Excellence for Climate System Science.
According to Ben Abbott, a researcher at the Institute of Arctic Biology at the University of Alaska, Fairbanks “there is compelling evidence, not just that the permafrost will thaw, but that it is already rapidly thawing.”
He went on to say “I think it’s easy for people to feel that the Arctic is just a far away place that will never have any direct impact on their life, but the last time a majority of permafrost carbon was lost to the atmosphere, temperatures increased by 6 degrees. That’s a different world. Too often climate change is depicted as a story of drowning polar bears. Human-induced climate change has the potential to change our way of life.”
Matthew Nott