Long established science
The theory of green house gas effect was first proposed in the 1820s. Further research in the 1850s and at the turn of the century to 1900s. It is not some new fad. It is well established science. It was studied again in the 1950s and the current intense focus has been going on since the 1970s.
You say
"Don't forget that 20000 years ago, humans were quite happily living in a climate we would regard as inimitable to life today"
Maybe, but they didn't have coastal cities to worry about and 6 billion people to feed etc.
Imagine todays modern world in either an ice age or a world where all the ice has melted, which is could do in coming centuries. If all the world's ice melts, the sea level will rise something like 270 feet. How many times will cities and agriculture and everything else have to be moved? You are just repeating standard deniar canaards that are not really helpful.
You say
- climates have changed since the atmospherere first formed. Therefore, climate change happens without human activity"
What kind of reasoning do you call that? You logic is absurd on the face of it. Fortunately, science works a little differently.
Okay, lets dispense with a few more silly denier arguments while we are at it.
"The Sun is causing he warming"
No its not. The solar activity has been very quiet for about 35 years now. We have been at a hundred year solar minimum since 1983. The study showing a correlation of warming with solar activity that skeptics like to point to as proof that the sun is the cause, comes to the exact opposite conlusion because of what my firstr two sentences say.
"Its Volcanos"
No its not. Man emits at least 100 times as much greenhouse gases as volcanos on average. Climate scientists have had a few good chances to study volcanos in recent years. Mt St Hellens in Washington state adn the big volcano in the Philippines in the 90s. Volcanos give off a lot of aerosols that act as atmospheric cooling agents by blocking incoming sunligtht.
Whats amazing is how many believe both of these arguments at the same time. If you debunk one, they bring up the other one. Actually most deniers believe all their arguments at the same time. Amazingly absurd.
"If global warming is real, why did scientists change the name to climate change?"
Nobody changed the name. Scientists have been using both terms since the mid 70s.
Ever hear of the Intergovernmental Panel on Global Warming? No of course you haven't, because its been called the Intergovernmental Panel on CLIMATE CHANGE since it was founded and named in 1988, 22 years ago.
""Climate scientists are doing it for the money."
No they're not. If they wanted to make big money they would go into the private sector where PhDs are paid well. The IPCC scientists do the work on their own time for FREE.
They aren't even paid.
"Climate scientists can't be trusted because they are paid with govt funds."
Most basic research in every field of science is govt funded. After academics do the basic research, industry picks up the information and develops products and new technologies from it. Your tax dollars at work, mostly benefitting the private sector business world.
"Al Gore is getting rich off global warming'
No he's not. He donates every penny to non profit groups for environmental education.
Oh, and his house is now energy efficient. Yes he flies around the world in big airplanes to educate people about global warming. To my mind, thats a pretty good trade off.
"Mann's "hockey stick" graph of temps is fake."
No its not. The chart has been reproduced about a dozen times by other scientists with the same result. It has been validated by the National Academy of Science. It has been validated by an investigation by the Universtiy of Pennsylvania, and by a thorough investigation of the climate gate issue by the Associated Press. The AP found no falsification of data whatsoever, by Mann or anyone else at the IPCC. The only study that found any fault with Mann's graph was the Wegman study for the U.S. senate and it was a rigged investigation that may lead to charges of perjury in a senate investigation. It was supposed to be unbiased. The National Academy of Science offered to do the study. But denier congresssman Barton chose a known denier with no science background instead. And the only difference in their chart was in the handle of the hockey stick, not in the blade, which is the part deniers don't believe, because is shows accelerated warming in this century. That's how deniers work. They can't beat the science, so they use mouthy amateurs like Monckton, Watts, McItrick, science fictioin writer Michael Crichton etc who can charm an audience and sound scientificky, without ever speaking a word of truth.
"John Coleman disagrees with the IPCC, and he founded the Weather Channel."
Right, and John Coleman isn't even a meteorologist, never mind a climate scientist. He is a TV personality who gives weather reports and is an avid anti envrionmentalist.
He likes to pretend he has some special skills but he's just another fraud.
Weather is not climate anyway.
"Its water vapor"
No its not. Water vapor is a feedback factor but not a cause of warming. The warmer it gets, the more water evaporates, accelerating the warming.
Roy Spencer and John Christy are both well known scientists among the climate change denier crowd . These two single handedly gave deniers amunition for a skeptic argument, about whether satellite data confirmed the global warming that the surface data showed. Deniers used this argument for a decade, encouraged by Spencer and Christy. It is well known that Spencer and Christy made serious and numerous errors in their data analysis. They were wrong. But this skeptic argument is still repeated all the time by deniers. Read more AT:
Climate Progress, search for Spencer and Christy
or at:
Real Climate " how to cook a graph in three easy lessons"
Argument:
It's so cold this winter in Peoria (fill in the location of your choice), what happened to global warming?
Answer:
That's not climate, that's weather. One week, month, winter or year are way too short to be meaningful, when talking about long term global climate change. Climate is measured over time periods of 30-100 years, not year to year fluctuations.
Argument:
Scientists in the 1970s were predicting global cooling. Why should we believe their warnings of global warming?
Answer:
Global Cooling in the 70s was NOT the issue. Seven scientific papers predicted cooling. The lead scientist recanted three years later, saying he had underestimated the amount of CO2 in the atomosphere. At the same time there were 42 scientific papers predicting global warming - AGW. So there were six times as many scientific papers predicting global warming as there were for global cooling. But the popular mass media got a hold of the cooling story and publicized it. That's why skeptics need to learn not to look to the popular press for their information. It rarely reflects the views of real climate scientists and certainly not the vast majority who support the IPCC findings.
Argument:
The earth has had much warmer climates in the past. What's so special about the current climate? Anyway, it seems like a generally warmer world will be better.
Answer
"I don't know if there is a meaningful way to define an "optimum" average temperature for planet earth. Surely it is better now for all of us than it was 20,000 years ago when so much land was trapped beneath ice sheets. Perhaps any point between the recent climate and the extreme one we may be heading for, with tropical forests inside the arctic circle, is as good as any other. Maybe it's even better with no ice caps anywhere.It doesn't matter. The critical issue is not what the temperature is, or may be, or will be. The critical issue is how fast it is moving.
Rapid change is the real danger. Human habits and infrastructure are suited to particular weather patterns and sea levels, as are ecosystems and animal behaviors. The rate at which global temperature is rising today is likely unique in the history of our species.
This kind of sudden change is rare even in geological history, though perhaps not unprecedented. So the planet may have been through similar things before -- that sounds reassuring, right?
Not so much. Once you look at the impact similar changes had on biodiversity at the time, the existence of historical precedent becomes anything but reassuring. Rapid climate change is the prime suspect in most mass extinction events, including the Great Dying some 250 million years ago, in which 90% of all life went extinct."
from Gristmill.com