via sciencealert:
Claims that the "the science isn’t settled" with regard to climate change are symptomatic of a large body of ignorance about how science works.
So what is the scientific method, and why do so many people, sometimes including those trained in science, get it so wrong?
The first thing to understand is that there is no one method in science, no one way of doing things. This is intimately connected with how we reason in general.
Science and reasoning
Humans have two primary modes of reasoning: deduction and induction. When we reason deductively, we tease out the implications of information already available to us.
For example, if I tell you that Will is between the ages of Cate and Abby, and that Abby is older than Cate, you can deduce that Will must be older than Cate.
That answer was embedded in the problem, you just had to untangle it from what you already knew. This is how Sudoku puzzles work. Deduction is also the reasoning we use in mathematics.
Inductive reasoning goes beyond the information contained in what we already know and can extend our knowledge into new areas. We induce using generalisations and analogies.
Generalisations include observing regularities in nature and imagining they are everywhere uniform – this is, in part, how we create the so-called laws of nature.
Generalisations also create classes of things, such as 'mammals' or 'electrons'. We also generalise to define aspects of human behaviour, including psychological tendencies and economic trends.
Analogies make claims of similarities between two things, and extend this to make new knowledge.
For example, if I find a fossilised skull of an extinct animal that has sharp teeth, I might wonder what it ate. I look for animals alive today that have sharp teeth and notice they are carnivores.
Reasoning by analogy, I conclude that the animal was also a carnivore.
Using induction and inferring to the best possible explanation consistent with the evidence, science teaches us more about the world than we could simply deduce.
Science and uncertainty
Most of our theories or models are inductive analogies with the world, or parts of it.
If inputs to my particular theory produce outputs that match those of the real world, I consider it a good analogy, and therefore a good theory. If it doesn’t match, then I must reject it, or refine or redesign the theory to make it more analogous.
If I get many results of the same kind over time and space, I might generalise to a conclusion. But no amount of success can prove me right. Each confirming instance only increases my confidence in my idea. As Albert Einstein famously said:
"No amount of experimentation can ever prove me right; a single experiment can prove me wrong."
Einstein’s general and special theories of relativity (which are models and therefore analogies of how he thought the universe works) have been supported by experimental evidence many times under many conditions.
We have great confidence in the theories as good descriptions of reality. But they cannot be proved correct, because proof is a creature that belongs to deduction.
The hypothetico-deductive method
Science also works deductively through the hypothetico-deductive method.
It goes like this. I have a hypothesis or model that predicts that X will occur under certain experimental conditions.
Experimentally, X does not occur under those conditions. I can deduce, therefore, that the theory is flawed (assuming, of course, we trust the experimental conditions that produced not-X).
Under these conditions, I have proved that my hypothesis or model is incorrect (or at least incomplete). I reasoned deductively to do so.
But if X does occur, that does not mean I am correct, it just means that the experiment did not show my idea to be false. I now have increased confidence that I am correct, but I can’t be sure.
If one day experimental evidence that was beyond doubt was to go against Einstein’s predictions, we could deductively prove, through the hypothetico-deductive method, that his theories are incorrect or incomplete. But no number of confirming instances can prove he is right.
That an idea can be tested by experiment, that there can be experimental outcomes (in principle) that show the idea is incorrect, is what makes it a scientific one, at least according to the philosopher of science Karl Popper.
As an example of an untestable, and hence unscientific position, take that held by Australian climate denialist and One Nation Senator Malcolm Roberts. Roberts maintains there is no empirical evidence of human-induced climate change.
When presented with authoritative evidence during an episode of the ABC’S Q&A television debating show recently, he claimed that the evidence was corrupted.
Yet his claim that human-induced climate change is not occurring cannot be put to the test as he would not accept any data showing him wrong. He is therefore not acting scientifically. He is indulging in pseudoscience.
Settled does not mean proved
One of the great errors in the public understanding of science is to equate settled with proved. While Einstein’s theories are 'settled',, they are not proved. But to plan for them not to work would be utter folly.
As the philosopher John Dewey pointed out in his book Logic: The Theory of Inquiry:
"In scientific inquiry, the criterion of what is taken to be settled, or to be knowledge, is [of the science] being so settled that it is available as a resource in further inquiry; not being settled in such a way as not to be subject to revision in further inquiry."
Showing posts with label anthropogenic. Show all posts
Showing posts with label anthropogenic. Show all posts
Tuesday, September 20, 2016
Monday, July 6, 2015
The oceans can’t take any more: Fundamental change in oceans predicted
via Disinformation:
Our oceans need an immediate and substantial reduction of anthropogenic greenhouse gas emissions. If that doesn’t happen, we could see far-reaching and largely irreversible impacts on marine ecosystems, which would especially be felt in developing countries. That’s the conclusion of a new review study published today in the journal Science. In the study, the research team from the Ocean 2015 initiative assesses the latest findings on the risks that climate change poses for our oceans, and demonstrates how fundamentally marine ecosystems are likely to change if human beings continue to produce just as much greenhouse gases as before.
Since the pre-industrial era, the carbon dioxide concentration in the atmosphere has risen from 278 to 400 ppm (parts per million) — a 40 percent increase that has produced massive changes in the oceans. “To date, the oceans have essentially been the planet’s refrigerator and carbon dioxide storage locker. For instance, since the 1970s they’ve absorbed roughly 93 percent of the additional heat produced by the greenhouse effect, greatly helping to slow the warming of our planet,” explains Prof Hans-Otto Pörtner, co-author of the new Ocean 2015 study and a researcher at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research.
But the oceans have also paid a high price: as far down as 700 metres the water temperatures have risen, which has forced some species to migrate up to 400 kilometres closer to Earth’s poles within the past decade. Given the increasing acidification in many regions, it’s becoming more and more difficult for corals and bivalves to form their calcium carbonate skeletons. In Greenland and the western Arctic, the ice is melting at an alarming rate, contributing to rising sea levels. As a result of these factors, the biological, physical and chemical processes at work in marine ecosystems are changing — which will have far-reaching consequences for marine life and humans alike.
In their new study, the research team from the Ocean 2015 initiative employs two emissions scenarios (Scenario 1: Achieving the 2-degree goal / Scenario 2: Business as usual) to compile the main findings of the IPCC’s 5thAssessment Report and the latest professional literature, and to assess those findings with regard to the risks for our oceans. “If we can successfully limit the rise in air temperature to two degrees Celsius through the year 2100, the risks, especially for warm-water corals and bivalves in low to middle latitudes, will become critical. However, the remaining risks will remain fairly moderate,” explains lead author Jean-Pierre Gattuso. But a rapid and comprehensive reduction of carbon dioxide emissions would be needed in order to achieve this ideal option, he adds.
If instead carbon dioxide emissions remain at their current level of 36 billion tonnes per year (the 2013 level), the situation will escalate dramatically. “If we just go on with business as usual, by the end of this century the changes will hit nearly every ecosystem in the oceans and cause irreparable harm for marine life,” claims Pörtner. This would in turn have massive impacts on all areas in which human beings use the oceans — whether in capture fisheries, tourism or in coastal protection.
Further, the researchers point out that with every further increase in the carbon dioxide concentration in the atmosphere, the available options for protecting, adapting and regenerating the oceans dwindle. As the authors summarise in the closing words of their study: “The ocean provides compelling arguments for rapid reductions in CO2 emissions and eventually atmospheric CO2 drawdown. Hence, any new global climate agreement that does not minimize the impacts on the ocean will be inadequate.”
The researchers’ statement above all addresses those individuals who will attend the international climate conference COP21 in Paris this December. Their study offers four key takeaway messages for the negotiators and decision-makers who will convene there:
1. The oceans greatly influence the climate system and provide important services for humans.
2. The impacts of anthropogenic climate change on key marine and coastal species can already be seen today. Many of these plant and animal species will face significant risks in the decades to come, even if we succeed in capping carbon dioxide emissions.
3. We urgently need an immediate and substantial reduction of carbon dioxide emissions in order to avoid widespread and above all irrevocable harm to ocean ecosystems and the services they provide.
4. Fourth, as atmospheric CO2 increases, the available protection, adaptation and repair options for the ocean become fewer and less effective, and with them the odds that marine life forms can successfully adapt to these rapid changes.
The Ocean 2015 initiative was launched to provide extensive information on the future of the oceans as a resource for decision-makers participating in the COP21 conference. The international research team is supported by thePrince Albert II of Monaco Foundation, the Ocean Acidification International Coordination Center of the International Atomic Energy Agency; the BNP Paribas Foundation and the Monégasque Association for Ocean Acidification.
Over the past several years, publications by researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, have greatly contributed to our current state of knowledge. One of the chief questions their efforts addresses is: “How will climate change affect ecosystems in the polar regions?.”
Our oceans need an immediate and substantial reduction of anthropogenic greenhouse gas emissions. If that doesn’t happen, we could see far-reaching and largely irreversible impacts on marine ecosystems, which would especially be felt in developing countries. That’s the conclusion of a new review study published today in the journal Science. In the study, the research team from the Ocean 2015 initiative assesses the latest findings on the risks that climate change poses for our oceans, and demonstrates how fundamentally marine ecosystems are likely to change if human beings continue to produce just as much greenhouse gases as before.
Since the pre-industrial era, the carbon dioxide concentration in the atmosphere has risen from 278 to 400 ppm (parts per million) — a 40 percent increase that has produced massive changes in the oceans. “To date, the oceans have essentially been the planet’s refrigerator and carbon dioxide storage locker. For instance, since the 1970s they’ve absorbed roughly 93 percent of the additional heat produced by the greenhouse effect, greatly helping to slow the warming of our planet,” explains Prof Hans-Otto Pörtner, co-author of the new Ocean 2015 study and a researcher at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research.
But the oceans have also paid a high price: as far down as 700 metres the water temperatures have risen, which has forced some species to migrate up to 400 kilometres closer to Earth’s poles within the past decade. Given the increasing acidification in many regions, it’s becoming more and more difficult for corals and bivalves to form their calcium carbonate skeletons. In Greenland and the western Arctic, the ice is melting at an alarming rate, contributing to rising sea levels. As a result of these factors, the biological, physical and chemical processes at work in marine ecosystems are changing — which will have far-reaching consequences for marine life and humans alike.
In their new study, the research team from the Ocean 2015 initiative employs two emissions scenarios (Scenario 1: Achieving the 2-degree goal / Scenario 2: Business as usual) to compile the main findings of the IPCC’s 5thAssessment Report and the latest professional literature, and to assess those findings with regard to the risks for our oceans. “If we can successfully limit the rise in air temperature to two degrees Celsius through the year 2100, the risks, especially for warm-water corals and bivalves in low to middle latitudes, will become critical. However, the remaining risks will remain fairly moderate,” explains lead author Jean-Pierre Gattuso. But a rapid and comprehensive reduction of carbon dioxide emissions would be needed in order to achieve this ideal option, he adds.
If instead carbon dioxide emissions remain at their current level of 36 billion tonnes per year (the 2013 level), the situation will escalate dramatically. “If we just go on with business as usual, by the end of this century the changes will hit nearly every ecosystem in the oceans and cause irreparable harm for marine life,” claims Pörtner. This would in turn have massive impacts on all areas in which human beings use the oceans — whether in capture fisheries, tourism or in coastal protection.
Further, the researchers point out that with every further increase in the carbon dioxide concentration in the atmosphere, the available options for protecting, adapting and regenerating the oceans dwindle. As the authors summarise in the closing words of their study: “The ocean provides compelling arguments for rapid reductions in CO2 emissions and eventually atmospheric CO2 drawdown. Hence, any new global climate agreement that does not minimize the impacts on the ocean will be inadequate.”
The researchers’ statement above all addresses those individuals who will attend the international climate conference COP21 in Paris this December. Their study offers four key takeaway messages for the negotiators and decision-makers who will convene there:
1. The oceans greatly influence the climate system and provide important services for humans.
2. The impacts of anthropogenic climate change on key marine and coastal species can already be seen today. Many of these plant and animal species will face significant risks in the decades to come, even if we succeed in capping carbon dioxide emissions.
3. We urgently need an immediate and substantial reduction of carbon dioxide emissions in order to avoid widespread and above all irrevocable harm to ocean ecosystems and the services they provide.
4. Fourth, as atmospheric CO2 increases, the available protection, adaptation and repair options for the ocean become fewer and less effective, and with them the odds that marine life forms can successfully adapt to these rapid changes.
The Ocean 2015 initiative was launched to provide extensive information on the future of the oceans as a resource for decision-makers participating in the COP21 conference. The international research team is supported by thePrince Albert II of Monaco Foundation, the Ocean Acidification International Coordination Center of the International Atomic Energy Agency; the BNP Paribas Foundation and the Monégasque Association for Ocean Acidification.
Over the past several years, publications by researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, have greatly contributed to our current state of knowledge. One of the chief questions their efforts addresses is: “How will climate change affect ecosystems in the polar regions?.”
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