h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I'm perplexed. I read recently the atmosphere consists of 78 percent nitrogen, 23 percent oxygen, 0.3 percent carbon dioxide, and 0.7 percent inert and other gases. Scientists tell us the greenhouse gases -- mostly carbon dioxide -- we're adding to the atmosphere are warming things up, changing climates, forcing species to extinction. My question is this: How can such a minuscule amount of carbon dioxide have such a profound impact on climate? If it were sugar in lemonade ––
and if you doubled the amount to 0.6 percent –– you’’d hardly notice the difference!

Actually, the minisucle amount of carbon dioxide DOESN'T have a profound impact on climate. The impact is just as miniscule as the amount. See here:

http://www.oism.org/pproject/s33p36.htm

If you double the amount of anything then that's a massive increase, it might not sound like much, but with the other greenhouse gasses, the man made CFCs, water vapour, methane, it all adds up to increasing global temperatures, sea level rise, more extreme weather (warm air holds more moisture, more rain), the possibility of the gulf stream slowing down, islands flooded.

Don't believe Mad Bush and his friends at the oil companies, or Jeremy Clarkson, time to find ways of reducing consumption.

what about a consequence of globabal warming, global freezing, brought on by the melting of the polar ice caps?

Over the last 50 years the ice pack covering the continent of antartica has decreased in size by 20%. That is a documented fact, also in the ice cores that are collected from antartica ther is a significant increas in the co2 levels since the onset, of the industrial revolution & they are rising year on year. your comment:-

Hmm I know this is selfish, but I worry more about the melting icecap's effect on the UK climate, given the increasing rate of coastal erosion, and that the colder waters may also divert the Gulf Stream, so we miss out on "Summer" altogether!

The data from the Vostok ice core has been cited as a proof that CO2 causes Global Warming. A graph of the data shows a close correspondence between the rise and fall of CO2 and temperature.
If CO2 causes the rise in temperature what causes the rise in CO2?
Analysis of the data reveals that the increase in CO2 lags behind the increase in temperature by about 800 years.
Having accepted this as fact 5? eminent climatologists who run the Real Climate web site stated:
“The reason has to do with the fact that the warmings take about 5000 years to be complete. The lag is only 800 years. All that the lag shows is that CO2 did not cause the first 800 years of warming, out of the 5000 year trend. The other 4200 years of warming could in fact have been caused by CO2, as far as we can tell from this ice core data.
The 4200 years of warming make up about 5/6 of the total warming. So CO2 could have caused the last 5/6 of the warming, but could not have caused the first 1/6 of the warming.”
This seems to me to be an unscientific explanation which does not explain another quite obvious fact that the temperature falls before the CO2
The only scource of CO2 sufficient to change its concentration in air is the sea. When the sea warms it releases CO2 when it cools it absorbs
CO2
Milankovitch explained why ice ages start by citing astronomical effects although in order to promote their theory the climatologists say that these effects are weak because during the ice ages they appear so, but this can explained because when there is a larger area of ice on the earth it reflects more sunlight and therefore it takes the coincidence of all the astronomical effects to end an ice age.

any person who believes in Global warming is a profound idiot, global warming is merely the result of the moons gravitational pull on the earth, so all this hype is just a scare of a natural process thats been happening for millions of years, why do you think we came out of the ice age, man wasnt industrialized enough to cause any harm to the enviroment, yet the atmosphere warmed up and the land became more condusive to living. Antarctica used to be a tropical area, scientists have found tropical plants under the ice, so as the earth turns its axis moves, bringing icy areas int the warm light and other tropical areas into the dark creating new ice ages in those areas.

Exactly. People need to chill out about the whole global warming thing. The climate changes all the time(from the Earth's perspective). I heard about this thing called the Ice Age, where the oceans froze, animals died, fjords were formed, lots of really great stuff. Guess what? EARTH IS STILL HERE! isn't that great? OK, so sea levels are rising, temperatures are rising, so what? Deal with it. You're not gonna stop it, so adapt to it. Isn't that what human beings are famous for(amongst themselves), adaptation? Isn't that why people can live in places like the himalayas, the deserts of the of the middle east, and New York?

And just in case you're one of those religious people who thinks the temperature is rising and famines and wars and sunamis are happening because people are sinning more than usual, and the Apocolypse is coming, you need to chill out, too. Do you know how many times things were happening and everybody said it was the end of the world? Lots. Black Plague, World Wars 1&2, every time they play country music on the radio. The world is probably not ending just yet. And if it is, then it is. It had too end sometime, right? But you can't really, stop it, so chill out.

And no, you are not necessarily and idiot(see post above this one)
If you are an idiot, I pity you.

I'm no expert onthe environment, but i'm still trying to do my bit to help. What right do we have to use all the resources and ruin the planet for future generations. I agree that the worlds climate is constantly changing and has been since it all began. The point is that mans actions are speeding up the process and the changes will be so quick that it will greatly effect millions of peoples lives.
Or should they just deal with it,

But the CO2 levels in the atmosphere are an indicator of the level of biological activity.

In glacials the earth is in a cold dry mode, in inter-glacials it's in a warm-wet mode. We're in a warm-wet interglacial. And if compare the extent of both ice sheet and desert now, to their extents in glacial phases. Then we can see that there is more viable land for plants, and hence animals, and for bacteria to live in the ecosystems created.

So in a cold-dry phase there is less biolgical activity. The seas, primarily, are then able to continue their uptake and fixing of CO2. CO2 falls from the levels of a warm-wet glacial. And the fall in CO2 exacerbates the original warming.

In a warm-wet phase (like now) there are extensive forests and tundra under what was ice-sheet. And areas that may have been desert are greened. So there is more biological activity and more of a reservoir of carbon in the land/air system. So the CO2 adds to astronomical factors to enhance the warming.

That's why there is a connection between the Milankovitch cycles and the atmospheric concentrations of CO2.

I'll try to get the time to post some supporting links for you over the weekend.

Anyone who is not a scientist who makes a statement like your is a "profound idiot" (see how that works?...No evidence = no argument).
Global warming has been caused by volcanic activity in the past; there is insufficient volcanic activity at present for this to be the cause in the rise in CO2. I would love to read your published evidence in the New Scientist soon.

I agree,


I think it is time for some experimental testing, instead of just all
these theories. I want to see some proof that the planet Earth is actually warming up.

I have an idea about a test that I believe could be performed, to prove that the temperature of the World's oceans (78% of the area of our planet), is actually getting warmer.

Here is how I believe this measurment can be achived: The density of water is related to temperature; And the speed of sound in water is related to the density of the water. Therefore I suggest that an international survey should be performed; By emitting a longwave signal through the waters of the Pacific Ocean, from the west coast of America to e.g New Zeeland or to the continent of Australia, and then measure the time taken for the the signal to travel over time.

I agree,

I think it is time for some experimental testing, instead of just all
these theories. I want to see some proof that the planet Earth is actually warming up.

I have an idea about a test that I believe could be performed, to prove that the temperature of the World's oceans (78% of the area of our planet), is actually getting warmer.

Here is how I believe this measurment can be achived: The density of water is related to temperature; And the speed of sound in water is related to the density of the water. Therefore I suggest that an international survey should be performed; By emitting a longwave signal through the waters of the Pacific Ocean, from the west coast of America to e.g New Zeeland or to the continent of Australia, and then measure the time taken for the the signal to travel over time.

This post has been removed.

Sorry for posting all this duplicate entries. I thought I was replying to each entry.
Sorry
/Mikael

Firstly, CO2 is not the most significant GHG in the atmosphere. That title goes to water vapour. In fact CO2 is one of the least effective greenhouse gases in the atmosphere at retaining radiative heat. Even methane is thousands of times more effective as a greenhouse gas.

Secondly, periods of volcanic activity/inactivity are absolutely not sufficient to explain previous warming compared with current warming. Moreover, different types of volcanic activity serve as positive and negative feedbacks, depending on the location of the activity and, among many other things, the role of water in the aerosol output.

There are two distinct periods of warming during the 20th century. Between the two was an extended period of cooling. In fact there is cumulatively as long a period of cooling in the 20th century as warming, despite a steady increase in anthropogenic atmospheric CO2 over the entire period.

Furthermore, the historical case, in ice-core, paleogeological and historical documentation, for the Medieval Warm Period, the Roman Warm Period and even the blisteringly warm Bronze Age Period, are compelling and indicate that during each of these periods the earth globally was warmer on average than it is today.

This means that natural variability can directly account for all of the relatively steady warming that we've experienced since the end of the Little Ice Age (~200 years ago). For the catastrophic anthropogenic global warming hypothesis to be considered scientific, it must be falsifiable. Because natural variability in the historical record is demonstrably greater than any anthropogenic warming signal, the global warming hypothesis is not falsifiable and therefore has not met the criteria in the Scientific Method to be considered a scientific hypothesis.

It is a travesty that pseudoscience has been permitted to pervade and corrupt the Scientific Method. Indeed, it has been embraced by political advocates for political causes.