Some of what people worry about when they look at the science of global warming all comes down to a matter of being a virtuous knower. Kant said 'dare to know for yourself', but with over 600 scientists involved in the IPCC assessment report, to say nothing of the endless blogs online, who do we trust? How can we individually challenge the science?
Christians are dedicated to the truth. Jesus claimed to be the truth and only path to the Father (Jn 14:6), the truth that sets free (Jn 8:32). In all affairs we are not to give false witness (Ex 20:16). You'd think Christians would be keen on following any inconvenient truth where ever it led.
Yet some might claim that the minds of scientists are darkened, most of the IPCC not being Christian. Paul notes that people suppress the truth about God (Rm 1:21). Yet Paul also acknowledges his own knowledge of God is limited and provisional (1 Cor 13:12), so it is kind of ironic that some Christians are most dogmatic in their denial of science they don't understanding. This is not to say that every aspect of climate science is understood 100%. Science is provisional in its understanding, but understanding can and does convergence about the 'truth'.
When we accuse non-Christians of bad motives in their science - consider how many of your doctors, nurses, mechanics, tradies, etc we all rely upon are also not Christians. Do they not possess wisdom and knowledge in their areas of expertise? Why do we deny the same to climate scientists, both Christian and non-Christian? Note the close parallel between Egyptian and some Hebrew wisdom literature (some of the Psalms and Proverbs) and it becomes harder to maintain that those who do not share our faith do not have real understanding of the world.
In assuming they bring non-science to their science, are we not doing the same? Dare we follow scientific 'truth' to its inconvenient implications?
Showing posts with label global warming. Show all posts
Showing posts with label global warming. Show all posts
Saturday, September 24, 2011
Monday, September 12, 2011
The costs are real - the Caretet Islanders
Local solutions on a sinking paradise, Carterets Islands, Papua New Guinea from UNUChannel on Vimeo.
The factors in this case are complex, which may include land use, water use, and some have also suggested tectonics. Regardless, the final cause of the progressive abandonment of these atolls is entirely consistent with sea level rise produced by global warming.
Images of climate change
Just been re-doing some lecture notes on evidence of climate change and found World View of Global Warming, with some compelling photographic evidence.
Thursday, July 28, 2011
Carbon dioxide sources
It is apparently not unusual among global warming skeptics to assert that volcanoes produce more carbon dioxide than human activities. However, a recent review of the literature in EOS, Transactions, American Geophysical Society show this not to be the case. Present day volcanoes emit about as much carbon dioxide annually as states like Florida, Michigan and Ohio.
Degassing by volcanoes forms part of the natural CO2 cycle, returning CO2 lost by weathering (turning CO2 into rock), formation of carbonate rocks and organic deposition (creatures dying). Rock that is subducted below plates eventually emerges in volcanoes which burp periodically (paroxysmal volcanic explosions) as well as the regular outgassing in sub-aerial and submarine volcanoes.
There is a range in annual emissions between 0.13 and 0.44 billion metric tons (gigtons) per year. Compare this to anthropogenic (human) sources in 2010 of 35 gigatons per year and you get the idea. These sorts of figures compare with countries like Pakistan (0.18 gigatons) or South Africa (0.44 gigatons). The most widely quoted and likely accurate study has the volcanic emissions at 0.26 gigatons per year. So what is the difference between anthropogenic and volcanic sources? A mere factor of 135!
The paroxysmal emissions sometimes match the human rate - so for example the 9 hour duration of Mt St Helens and Mt Pinatubo reached 0.001-0.006 gigtons per hour, compared to the 0.004 gigtons per hour from anthropogenic sources. While the rates are similar, the timescales are very different.
What is more, to blame current global emissions on volcanoes would require a startling amount of activity. The amount of magma that would be required to match the amount of carbon would be some 40 times the annual mid-ocean ridge amount of magma production. Another way of looking at it would to ask how many volcanoes would be required to account for 2010 CO2 emissions. The number is about 9500! One could deliver the 35 gigatons per year via paroxysmal eruptions, it would only take about 700 Mt Pinatubos per year.
Perhaps it really is easier to believe fossil fuel burning, land clearing etc are responsible.
Degassing by volcanoes forms part of the natural CO2 cycle, returning CO2 lost by weathering (turning CO2 into rock), formation of carbonate rocks and organic deposition (creatures dying). Rock that is subducted below plates eventually emerges in volcanoes which burp periodically (paroxysmal volcanic explosions) as well as the regular outgassing in sub-aerial and submarine volcanoes.
There is a range in annual emissions between 0.13 and 0.44 billion metric tons (gigtons) per year. Compare this to anthropogenic (human) sources in 2010 of 35 gigatons per year and you get the idea. These sorts of figures compare with countries like Pakistan (0.18 gigatons) or South Africa (0.44 gigatons). The most widely quoted and likely accurate study has the volcanic emissions at 0.26 gigatons per year. So what is the difference between anthropogenic and volcanic sources? A mere factor of 135!
The paroxysmal emissions sometimes match the human rate - so for example the 9 hour duration of Mt St Helens and Mt Pinatubo reached 0.001-0.006 gigtons per hour, compared to the 0.004 gigtons per hour from anthropogenic sources. While the rates are similar, the timescales are very different.
What is more, to blame current global emissions on volcanoes would require a startling amount of activity. The amount of magma that would be required to match the amount of carbon would be some 40 times the annual mid-ocean ridge amount of magma production. Another way of looking at it would to ask how many volcanoes would be required to account for 2010 CO2 emissions. The number is about 9500! One could deliver the 35 gigatons per year via paroxysmal eruptions, it would only take about 700 Mt Pinatubos per year.
Perhaps it really is easier to believe fossil fuel burning, land clearing etc are responsible.
Tuesday, July 19, 2011
Monday, May 30, 2011
I bought a new car - should I feel guilty?
The time has come, I bought a new car on Saturday. I drove my dad's car for 15 years - a 1981 Mazda 323. It was time for a change, the car was old, fuel inefficient and with a twice or more reconditioned carburetor I suspect a big producer of pollution. So I bought a new Mazda, but did I need to?
Each of us needs to ask the question: ever since seeing the documentary What would Jesus Drive? I've realised cars are a big idol in the west, a symbol of our control over nature, our own pleasure (how many car adds are about benefits and lifestyle instead of features) and individual autonomy. People who live in a city like Melbourne with (for all its faults) an extensive public transport system can afford to get by a lot without using your car too often. I love the tram and am able to get into work via it, also sports events, concerts etc. Shopping, my sporting involvement and church (from an Anglican point of view I live outside the parish I attend).
How will I drive virtuously? By using it less, especially when public transport is sufficient. Car pooling and offering lifts are also good activities to use a car for. Finally, partly due to car repayments but also given the emissions from air travel, some of our holidays will involve use of the car rather than air. It will be a constant tension - at least until electric cars are mainstream.
Each of us needs to ask the question: ever since seeing the documentary What would Jesus Drive? I've realised cars are a big idol in the west, a symbol of our control over nature, our own pleasure (how many car adds are about benefits and lifestyle instead of features) and individual autonomy. People who live in a city like Melbourne with (for all its faults) an extensive public transport system can afford to get by a lot without using your car too often. I love the tram and am able to get into work via it, also sports events, concerts etc. Shopping, my sporting involvement and church (from an Anglican point of view I live outside the parish I attend).
How will I drive virtuously? By using it less, especially when public transport is sufficient. Car pooling and offering lifts are also good activities to use a car for. Finally, partly due to car repayments but also given the emissions from air travel, some of our holidays will involve use of the car rather than air. It will be a constant tension - at least until electric cars are mainstream.
Wednesday, May 25, 2011
recent environmental press releases
Invasive species
A recent press release on the Mediterranean shows that the continued introduction of invasive species (something that happens via ballast water but also of course the Suez Canal) can have serious impacts on local ecosystems.
Extinctions
Species extinctions are often tied to modern society with land clearing, over hunting or fishing etc. However, a recent press release here and the free to public study here, show that the Polynesians were responsible for the extinction of a Hawaiian land crab over 1000 years ago. These crabs are major predators, control litter decomposition and help in nutrient cycling and seed dispersal. Their disappearance was caused by the arrival of humans to the islands and resulted in large-scale changes in the state's ecosystem.
Emissions trading
Recent work in emissions trading has shown that pollution hotspots have not been created in poor and minority areas in the US. In particular, it appears as if the sulfur dioxide allowance trading program appears to be working well, and not to the detriment of the poor.
Impacts of ocean warming
A recent report shows that surface water temperatures in the Tasman Sea have risen by nearly 2°C over the past 60 years. The study finds that "ocean warming has pushed the banded morwong -- which inhabits temperate reefs in waters 10-50m deep -- past the point where increasing temperatures are beneficial to growth." This is one of the first studies that shows the impacts of ocean warming on fish in our region.
A recent press release on the Mediterranean shows that the continued introduction of invasive species (something that happens via ballast water but also of course the Suez Canal) can have serious impacts on local ecosystems.
Extinctions
Species extinctions are often tied to modern society with land clearing, over hunting or fishing etc. However, a recent press release here and the free to public study here, show that the Polynesians were responsible for the extinction of a Hawaiian land crab over 1000 years ago. These crabs are major predators, control litter decomposition and help in nutrient cycling and seed dispersal. Their disappearance was caused by the arrival of humans to the islands and resulted in large-scale changes in the state's ecosystem.
Emissions trading
Recent work in emissions trading has shown that pollution hotspots have not been created in poor and minority areas in the US. In particular, it appears as if the sulfur dioxide allowance trading program appears to be working well, and not to the detriment of the poor.
Impacts of ocean warming
A recent report shows that surface water temperatures in the Tasman Sea have risen by nearly 2°C over the past 60 years. The study finds that "ocean warming has pushed the banded morwong -- which inhabits temperate reefs in waters 10-50m deep -- past the point where increasing temperatures are beneficial to growth." This is one of the first studies that shows the impacts of ocean warming on fish in our region.
Thursday, May 19, 2011
Coasts, oceans and greenhouse gases
An interesting piece has appeared in today's Nature magazine about the state of play of conservation issues in Brazil, namely coastal areas such as mangroves and sea grasses. Brazil contains 80% of the remaining Amazon forest and has been the focus of efforts to protect them but at the same time commercialise them. I won't go into arguments about the commercialisation of such rainforests except to say that Brazilians won't settle for a lower level of living compared to the rest of the developed world - which raises issues about our standard of living and whether it is sustainable.
But as the article states, while much emphasis has been placed on rainforest, what about coastal ecosystems such as mangroves? These swamps store large amounts of carbon in their thick, gelatinous mud. They cover just 0.5% of marine areas, but are among the largest carbon sinks in the ocean. Typically, they store up to 15 times more carbon per hectare than terrestrial soils, absorbed over hundreds or even thousands of years, and sequester carbon 10–50 times faster than terrestrial forests.
Sadly, between 30% and 50% of mangroves have disappeared in the past 50 years; about 30% of the world's seagrasses are gone; and half of the global coverage of salt marshes has been destroyed. Stresses include agriculture run off, fisheries and of course straight out land clearing. As well as storing carbon, mangroves are fish hatcheries. A greater emphasis needs to be placed on their preservation in climate talks and controls on the local and global scale.
But as the article states, while much emphasis has been placed on rainforest, what about coastal ecosystems such as mangroves? These swamps store large amounts of carbon in their thick, gelatinous mud. They cover just 0.5% of marine areas, but are among the largest carbon sinks in the ocean. Typically, they store up to 15 times more carbon per hectare than terrestrial soils, absorbed over hundreds or even thousands of years, and sequester carbon 10–50 times faster than terrestrial forests.
Sadly, between 30% and 50% of mangroves have disappeared in the past 50 years; about 30% of the world's seagrasses are gone; and half of the global coverage of salt marshes has been destroyed. Stresses include agriculture run off, fisheries and of course straight out land clearing. As well as storing carbon, mangroves are fish hatcheries. A greater emphasis needs to be placed on their preservation in climate talks and controls on the local and global scale.
Friday, May 6, 2011
Cereal killers - global warming and the end of the agricultural miracle
Thomas Malthus predicted a time when there would be too many people to feed on the planet. In the 70s the Club of Rome with people like Paul Elrich said similar but were mocked and shown to be wrong. Fossil fuels, chemical fertilisers etc saw an agricultural boom, but dead zones in our oceans, toxic algal blooms and depleted soils should point to this being a mixed blessing. Likewise, nitrogen ends up as NO2, a greenhouse gas. Humans fix more nitrogen for agriculture than all other sources.
And now as if all these impacts of intensive agriculture were not enough, a new study reported in Scientific American shows that global warming is producing a decline in cereal yields. It seems while increased CO2 increases yields, increasing temperatures adversely affect yields, particularly wheat. Apparently, this is already evident in increased prices as yields decline.
And now as if all these impacts of intensive agriculture were not enough, a new study reported in Scientific American shows that global warming is producing a decline in cereal yields. It seems while increased CO2 increases yields, increasing temperatures adversely affect yields, particularly wheat. Apparently, this is already evident in increased prices as yields decline.
Thursday, May 5, 2011
Recent Scientific American articles
There are a few environment related articles posted recently on the Scientific American website.
One relates to the Martian atmosphere. The study of other planetary atmospheres tells us something about our own. In the case of Mars, being smaller than the Earth, much of its atmosphere escaped some time ago, but a lot of CO2 has been discovered under its surface, enough to warm the planet should temperatures increase. It turns out there could be a regular cycle as the axis of rotation of Mars varies much more over time than our own, due to the stabilising influence of our massive moon (I'm reminded of Genesis 1:16). The change in tilt means from time to time the CO2 buried in the polar regions could melt and hence warm the planet. It is a reminder to us of the power of Greenhouse gases.
Another article examines ice cores for evidence of rapid warming in the geological past. James White has not only found that in the past a change in 100 ppm of CO2 has made the difference between flowers blooming in the Arctic and ice a mile deep over Chicago. The paleo-climate record also shows that dramatic changes have occurred in the past due to warming in a matter of decades, not centuries.
An article on Richard Branson's plan to relocate some endangered lemurs to a couple of his own private islands(!) has drawn flack from conservationists about impacts on the pre-existing species by predation, disease, etc. It opens up issues about how we go about conserving species (Madagascar's forests are rapidly disappearing) and who decides how.
Finally, an article on the Gulf oil spill shows there is still a lot of oil out there in the Gulf, and that drilling will be a part of the economy there for some time to come.
One relates to the Martian atmosphere. The study of other planetary atmospheres tells us something about our own. In the case of Mars, being smaller than the Earth, much of its atmosphere escaped some time ago, but a lot of CO2 has been discovered under its surface, enough to warm the planet should temperatures increase. It turns out there could be a regular cycle as the axis of rotation of Mars varies much more over time than our own, due to the stabilising influence of our massive moon (I'm reminded of Genesis 1:16). The change in tilt means from time to time the CO2 buried in the polar regions could melt and hence warm the planet. It is a reminder to us of the power of Greenhouse gases.
Another article examines ice cores for evidence of rapid warming in the geological past. James White has not only found that in the past a change in 100 ppm of CO2 has made the difference between flowers blooming in the Arctic and ice a mile deep over Chicago. The paleo-climate record also shows that dramatic changes have occurred in the past due to warming in a matter of decades, not centuries.
An article on Richard Branson's plan to relocate some endangered lemurs to a couple of his own private islands(!) has drawn flack from conservationists about impacts on the pre-existing species by predation, disease, etc. It opens up issues about how we go about conserving species (Madagascar's forests are rapidly disappearing) and who decides how.
Finally, an article on the Gulf oil spill shows there is still a lot of oil out there in the Gulf, and that drilling will be a part of the economy there for some time to come.
Thursday, April 28, 2011
Euthanasia and global warming
A friend passed around a link on Facebook to a poll in the Northern Territory about euthanasia laws. Now don't get me wrong, I find the idea of sanctioned killing of the old or suffering disturbing, saddening and in the end morally disagreeable, and would never want to see it legislated. There has been great advances in palliative care and it reflects far better on a society that people are cared for in their suffering. One might pull out the usual argument that we play God when we choose the timing of our own deaths.
However, we do drug up people in pain, and I imagine some people who are old and frail have little conscious experience because of this, to say nothing of the morally complex cases of people on life support. When does quality of life ebb so low that it isn't worth living? Does God desire us to suffer? Some would respond with comments about character, etc, but suffering in any form is an evil even if it can result in a good. In the end I'd rather see such laws opposed and more put into care for those who suffer.
So why bring global warming into this? Well it is usually going to be the old who are going to be euthanased. And it is the very old who suffer directly from global warming. In 2003, Europe suffered a huge heat wave during summer. It is estimated that some 35,000 people died as a result of the heat wave. The summer temperatures in Europe for example were some 5 standard deviations away from the mean values, i.e. it was an extreme event. Comparisons of temperatures between the late half of the 19th and early part of the 20th, and the second half of the 20th c. saw a change in the mean temperature of about 1 C. A recent study showed that this heat wave is four times more likely to occur in our warmed climate than in a pre-industrial atmosphere. Future scenarios for Europe show up to 4 C warming by the end of the century with 100% change in temperature variability, making a rare event common.
Most of those who died in the heat wave were the elderly, who are often already dehydrated, have heart issues, problems thermo-regulating, etc. Euthanasia is the decision to die, right or wrong. Global warming is already killing the elderly in extreme events in the civilised West. We know global warming is real - so why campaign on euthanasia but not on global warming? Same goes with abortion. Complex issue, sad, terminating young lives. With water already being a problem in the developing world, dirty water causing many deaths by diarrhea, how much more so will the poor children die in the warming climate? Why campaign against abortion in the west yet let children die elsewhere?
Christian ethics should not just be about standard life/death issues.
However, we do drug up people in pain, and I imagine some people who are old and frail have little conscious experience because of this, to say nothing of the morally complex cases of people on life support. When does quality of life ebb so low that it isn't worth living? Does God desire us to suffer? Some would respond with comments about character, etc, but suffering in any form is an evil even if it can result in a good. In the end I'd rather see such laws opposed and more put into care for those who suffer.
So why bring global warming into this? Well it is usually going to be the old who are going to be euthanased. And it is the very old who suffer directly from global warming. In 2003, Europe suffered a huge heat wave during summer. It is estimated that some 35,000 people died as a result of the heat wave. The summer temperatures in Europe for example were some 5 standard deviations away from the mean values, i.e. it was an extreme event. Comparisons of temperatures between the late half of the 19th and early part of the 20th, and the second half of the 20th c. saw a change in the mean temperature of about 1 C. A recent study showed that this heat wave is four times more likely to occur in our warmed climate than in a pre-industrial atmosphere. Future scenarios for Europe show up to 4 C warming by the end of the century with 100% change in temperature variability, making a rare event common.
Most of those who died in the heat wave were the elderly, who are often already dehydrated, have heart issues, problems thermo-regulating, etc. Euthanasia is the decision to die, right or wrong. Global warming is already killing the elderly in extreme events in the civilised West. We know global warming is real - so why campaign on euthanasia but not on global warming? Same goes with abortion. Complex issue, sad, terminating young lives. With water already being a problem in the developing world, dirty water causing many deaths by diarrhea, how much more so will the poor children die in the warming climate? Why campaign against abortion in the west yet let children die elsewhere?
Christian ethics should not just be about standard life/death issues.
Friday, February 25, 2011
Thursday, February 24, 2011
Stephen Hawking and Carl Sagan on the Greenhouse effect
Between Venus and pre-industrial Earth is a range of worlds from permitting life as we know it, to large adjustments to society and ecosystem impoverishment, to societal collapse and ecosystem collapse, and finally to the destruction of everything. Between the two extremes is our future. Let's act now to make it a good future.
Sunday, February 6, 2011
Christians and Earth Hour
Earth Hour started in Sydney in 2007, calling on individuals and busineses to recognise the threat of anthropogenic global warming (AGW) by switching off lights and other electrical appliances for just one hour. It has now spread as a global movement. Its webpage is found here and Facebook page here.
One may wonder at the value of this, after all 1 hour won't make much difference to the amount of green house gases (GHGs) the word emits. So isn't this empty symbolism? And what does some "pointless" event have to do with the church and individual Christians?
Firstly, Earth Hour recognises that AGW is real, something not enough Christians do. If you don't believe it is happening, it is our fault and the impacts are going to be serious (and are being in some places already) then you are not looking carefully enough at the science, and indeed at your own epistemology and ideology. Some sections of the church are woefully behing in this, indeed risk being "Left Behind" in its mission to live out proleptically the future shalom, that holistic restoration of creation.
Secondly, the church most of all should be accustomed to symbolism, outward signs of inner transformations, first fruits of greater realities, etc. No one says that Earth Hour will save the world (of course only Christ can do that), but it is a taste of action required and a visible commitment to that change.
Thirdly, as a people in exile, the church like Israel should work for the well being of the society of which it is a part. Working with people of all faiths or none means getting on board with whatever is going, while retaining our distinctives. So here's a few ideas.
1. Have a prayer service by candlelight, praying for Christ to return to bring the creation to rights, the non-human and evil and sin.
2. Celebrate communion, remembering that bread and wine are the fruits of the Earth we have been called to care for.
3. Enjoy a meal prepared from your or someone else's garden, or a low carbon meal (which usually means vego) and remember our connection to the earth as humans from the humus.
4. Eat simply and remember the starving millions, especially those already displaced by AGW or suffering due to droughts or floods exaccerbated by AGW. Ask for forgiveness for covetousness and greed.
5. Host an event (could even be by candlelight) discussing Christian spirituality and the environmental crisis. Christian spirituality can align with this event in so many ways.
It's God's world, given to us made in his image to care for. Don't be left behind on Earth Hour.
Earth Hour 2011: 8.30pm, Saturday 26 March
One may wonder at the value of this, after all 1 hour won't make much difference to the amount of green house gases (GHGs) the word emits. So isn't this empty symbolism? And what does some "pointless" event have to do with the church and individual Christians?
Firstly, Earth Hour recognises that AGW is real, something not enough Christians do. If you don't believe it is happening, it is our fault and the impacts are going to be serious (and are being in some places already) then you are not looking carefully enough at the science, and indeed at your own epistemology and ideology. Some sections of the church are woefully behing in this, indeed risk being "Left Behind" in its mission to live out proleptically the future shalom, that holistic restoration of creation.
Secondly, the church most of all should be accustomed to symbolism, outward signs of inner transformations, first fruits of greater realities, etc. No one says that Earth Hour will save the world (of course only Christ can do that), but it is a taste of action required and a visible commitment to that change.
Thirdly, as a people in exile, the church like Israel should work for the well being of the society of which it is a part. Working with people of all faiths or none means getting on board with whatever is going, while retaining our distinctives. So here's a few ideas.
1. Have a prayer service by candlelight, praying for Christ to return to bring the creation to rights, the non-human and evil and sin.
2. Celebrate communion, remembering that bread and wine are the fruits of the Earth we have been called to care for.
3. Enjoy a meal prepared from your or someone else's garden, or a low carbon meal (which usually means vego) and remember our connection to the earth as humans from the humus.
4. Eat simply and remember the starving millions, especially those already displaced by AGW or suffering due to droughts or floods exaccerbated by AGW. Ask for forgiveness for covetousness and greed.
5. Host an event (could even be by candlelight) discussing Christian spirituality and the environmental crisis. Christian spirituality can align with this event in so many ways.
It's God's world, given to us made in his image to care for. Don't be left behind on Earth Hour.
Earth Hour 2011: 8.30pm, Saturday 26 March
Big coal = big bully
Excellent piece by Clive Hamilton here. Of course the obvious retort is that light bulbs don't run on good intentions, but when we should be moving (and quickly) to cleaner sources of energy, letting corporations run all over free speech and crushing the little person is anti-democracy.
Militarism and climate change
Takes a lot of energy to run a military = a lot of green house gases. Empires have always been associated with environmental damage, back to the deforestation by Rome to build there ships. Interesting piece here thank links the huge American military to environmental degredation. A reminder that the Prince of Peace comes to bring shalom - which means and end to all wars and rest for the earth.
Thursday, February 3, 2011
Yasi, La Nina & Climate change
A nice piece appeared on the ABC website here.
La Nina is the opposite of El Nino. It occurs when the sea surface temperatures in the western Pacific/Coral Sea are warmer than usual and the winds across the Pacific are stronger than usual. A measure of the strength of this circulation is the Southern Oscillation Index or SOI, which is a measure of pressure differences across the Pacific. Pressure differences are related to temperature differences and hence produce differences in the win strength. Apparently it was 27.1 in December, the highest ever measured. Hence, while floods and Tropical Cyclones like those observed have occurred before, the conditions that have caused them appear to be unusual.
Dr Andrew Ash of the CSIRO suggests part of this is due to global warming, producing the lower than usual pressures over the western Pacific. This reinforces the idea that flooding and strong TCs are expected to increase in frequency under human-induced global warming, even if the mean trend is drying in our part of the world.
La Nina is the opposite of El Nino. It occurs when the sea surface temperatures in the western Pacific/Coral Sea are warmer than usual and the winds across the Pacific are stronger than usual. A measure of the strength of this circulation is the Southern Oscillation Index or SOI, which is a measure of pressure differences across the Pacific. Pressure differences are related to temperature differences and hence produce differences in the win strength. Apparently it was 27.1 in December, the highest ever measured. Hence, while floods and Tropical Cyclones like those observed have occurred before, the conditions that have caused them appear to be unusual.
Dr Andrew Ash of the CSIRO suggests part of this is due to global warming, producing the lower than usual pressures over the western Pacific. This reinforces the idea that flooding and strong TCs are expected to increase in frequency under human-induced global warming, even if the mean trend is drying in our part of the world.
Friday, January 28, 2011
Arctic current warmer than for 2,000 years
Arctic warms faster as melting ice uncovers darker ground or open waters - bad news. Article here.
Tuesday, January 25, 2011
Droughts and flooding rains
A couple of sensibly written pieces to show how vapid and shallow Bolt et al are in their understanding.
Sydney Morning Herald piece looks at how global warming can increase the likelihood of disasters here.
Piece by former CSIRO atmospheric research head Graeme Pearson on global warming, Hadley Cell and drying Australia here.
Sydney Morning Herald piece looks at how global warming can increase the likelihood of disasters here.
Piece by former CSIRO atmospheric research head Graeme Pearson on global warming, Hadley Cell and drying Australia here.
Friday, January 21, 2011
Bolt shooting his mouth off again
Not even worth bothering providing a link to his tripe - apparently neither the drought nor the recent flooding rains are due to global warming. Ok I will here
As explained before - while a single event cannot be tied without question to global warming - the following remarks may be made.
1. There has beena decine in annual rainfall over eastern Australia.
2. Part of this is due to global warming. A study can be found here. Something else to review at some point.
3. The natural cycle of El Nino/La Nina will naturally lead to variability in rainfall.
4. Warmer temperatures means more evaporation and can increase atmospheric moisture, leading to heavy rainfall events.
Bolt is an ideologue, with little scientific sophistication and blogging a few quotes speaking about drought with an 'I told you so' tone proves little except to those whose politics and/or theology pre-disposes them to accept his ranting.
As explained before - while a single event cannot be tied without question to global warming - the following remarks may be made.
1. There has beena decine in annual rainfall over eastern Australia.
2. Part of this is due to global warming. A study can be found here. Something else to review at some point.
3. The natural cycle of El Nino/La Nina will naturally lead to variability in rainfall.
4. Warmer temperatures means more evaporation and can increase atmospheric moisture, leading to heavy rainfall events.
Bolt is an ideologue, with little scientific sophistication and blogging a few quotes speaking about drought with an 'I told you so' tone proves little except to those whose politics and/or theology pre-disposes them to accept his ranting.
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