20 replies to this topic

[Blade]

I hadnt heard this theory about the sun getting closer/ more intense. I think whether its true or not, global warming's at least partly our fault.
And (optimistically) the world will eventually end anyway, when the sun burns out or something. Just to be cheerful.
I'm not saying we should just give up, though, but I doubt we could change the damage we've done much now unless everyone tried, not just a few countries.
I might be wrong, I dont know.

HAHAHAHAHAHAHAHA!!!!!!!! THE SUN GETTING CLOSER?!?!?! THATS FUNNY!

Usually it's the earth that moves, not the sun

[Violent pedestrian]

Well, I meant the sun and earth getting closer together. But I guess I did sort of write it like that.
I hadnt heard the sun theory anyway, whatever it is.

[foolonthehill]

Wow. I'm surprised to see so much skepticism here. Maybe it's a US thing: I heard that there were many objectors to the CO₂ theory in the US, but thought you'd got past that now. I may be completely wrong, but I would imagine that a Europe dominated discussion would be much more accepting of greenhouse gas theories and critical of man's influence.

So, let's clear up a few things:
- there is no suggestion that the Earth is changing its distance from the sun by an influential amount (other planets, etc do change our position, but not our orbit). However, sun spots etc do cause the radiation we receive to change quite substantially. These are in cycles of enormously varying periods, so are generally unpredictable.
- there are certainly cycles in the Earth's temperature, also with varying periods, so we could suggest that this is all natural. That's becoming a difficult argument as temperatures begin to change so drastically.
- there is a clear correlation between the temperature of the Earth and the quantity of greenhouse gases in our atmosphere since the start of the industrial revolution, as Bb stated. However, this doesn't mean that they are necessarily linked, but as temperatures continue to rise at an ever increasing rate, there are increasingly few alternative explanations.
- a warmer overall Earth has little relation to local temperatures. The best example being the UK: look at an atlas and marvel at how far north we are - the same latitude as Siberia or Canada. However, for various reasons, such as the Gulf Stream (a warm mass of water that comes up the east coast of the US and across the northern Atlantic), we have a very temperate climate. The chances are that global warming by a couple of degrees could turn us into a frozen wilderness (assuming we don't flood first ).
- The Day After Tomorrow is scientifically rubbish.


I think most of the world (certainly the vast majority of scientists) is now clear that Global warming is happening and therefore, I'd say the cause is somewhat irrelevant. More important is how we respond to it. The most interesting reads I've had recently is this one: Scientific American

[Blade]

Wow. I'm surprised to see so much skepticism here. Maybe it's a US thing: I heard that there were many objectors to the CO₂ theory in the US, but thought you'd got past that now. I may be completely wrong, but I would imagine that a Europe dominated discussion would be much more accepting of greenhouse gas theories and critical of man's influence.

So, let's clear up a few things:
- there is no suggestion that the Earth is changing its distance from the sun by an influential amount (other planets, etc do change our position, but not our orbit). However, sun spots etc do cause the radiation we receive to change quite substantially. These are in cycles of enormously varying periods, so are generally unpredictable.
- there are certainly cycles in the Earth's temperature, also with varying periods, so we could suggest that this is all natural. That's becoming a difficult argument as temperatures begin to change so drastically.
- there is a clear correlation between the temperature of the Earth and the quantity of greenhouse gases in our atmosphere since the start of the industrial revolution, as Bb stated. However, this doesn't mean that they are necessarily linked, but as temperatures continue to rise at an ever increasing rate, there are increasingly few alternative explanations.
- a warmer overall Earth has little relation to local temperatures. The best example being the UK: look at an atlas and marvel at how far north we are - the same latitude as Siberia or Canada. However, for various reasons, such as the Gulf Stream (a warm mass of water that comes up the east coast of the US and across the northern Atlantic), we have a very temperate climate. The chances are that global warming by a couple of degrees could turn us into a frozen wilderness (assuming we don't flood first ).
- The Day After Tomorrow is scientifically rubbish.


I think most of the world (certainly the vast majority of scientists) is now clear that Global warming is happening and therefore, I'd say the cause is somewhat irrelevant. More important is how we respond to it. The most interesting reads I've had recently is this one: Scientific American

Actually... the day afer tomarrow can really happen. Just alot of factors have to be in the right place at the right time.

[Prof. Templeton]

The only thing I'm not convinced about in regard to global warming and greenhouse gases is the role that CO2 plays in the equation. It is true that there are direct corelations between the the amount of CO2 and the Earth's temperature, but what Al Gore didn't mention is that the amount of CO2 in the atmosphere historiclly lags behind changes in global temperature. So yes the graphs are almost identical in their peaks and furrows, but a peak in temperature will be followed by a peak in CO2 amounts. I believe if we concentrate all our efforts into reducing CO2 emmisions we may have wasted time and resources when there are other reasons that we should be looking at and other projects that may be a better use of our money. Humans can only claim responsiblity for 3.4% of the CO2 emmitted each year, the rest is all natural. It just seems that CO2 is being painted as a pollutant when it's quite essential for life. IMO.

[guest_7314]

I had never noticed the earth getting warmer. I did read about the North pole slowly melting and becoming nonexistent in many years to come. I don't believe there is anything we can do about the sun getting closer. At least, that is what seems to be happening. I think this past summer was cooler than what I noticed in the past. I say not to panic, until we have more to go on.

Haven't you been reading, watching or listening to the news?! Is that all you do on your computer? Going on BrainDen? HAHAHA!!!!!!

[guest_7314]

HAHAHAHAHAHAHAHA!!!!!!!! THE SUN GETTING CLOSER?!?!?! THATS FUNNY!

Usually it's the earth that moves, not the sun

What do you mean? The sun moves around our galaxy (The Milky Way).

[foolonthehill]

Actually... the day afer tomarrow can really happen. Just alot of factors have to be in the right place at the right time.

I put that in because I'd mentioned the gulf stream and thought that someone might think I was basing my argument off it! But it's a film, destined for entertainment, and because they know that reality makes far less enjoyable watching. 'Abrupt' climate definitely would not happen as the film portrayed.

While the general idea of extreme climate changes are (possibly) realistic, in climate terms 'abrupt' means about 5 years minimum, and probably more like 50. The suggestion that an ice age (which would need to come after more significant global warming in most scenarios) could cover the earth in a matter of days is patently wrong IMHO. The whole bit about instantly freezing super-cell storms are unrealistic too. Firstly, hurricanes can only form over water, as it is water vapour that makes/drives them, and, secondly, it would (almost) impossible for air of such low temperatures to rapidly find its way down to the surface, without almost equally rapid warming of the air as it moves.

To be honest, I've not seen the film much more than once, mainly because these type films always have a couple of scientific mistakes which rile me so much that I can't enjoy them properly!

And, in response to Prof T, what is so concerning about greenhouse gas levels, is that very small changes in percentage can have very big impacts on temperature and climate. Yes, humans produce very small amounts of greenhouse gases compared to natural means (depending slightly on whether you blame us for farting cows! ), but our small increase, results in a bigger change elsewhere for the global ecosystem to compensate. However, I agree that reducing our emissions now (despite being nearly impossible) is somewhat futile - I'm all for the geoengineering projects of the type I put in my last post.

[Lost in space]

I like Bb large post and its very interesting. The fact that he also adds a two line thought and makes his point - concise summing up.
We all have too little time to debate it properley. No one can say man has no impact on it or very little. The fact is that nature itself over balances too and corerects itself again - was it a good thing the dinosaurs were caught up in one of natures overbalances - it didn't do the human race harm n the long run. We are making huge mistakes in effective controls to reduce our effect on the environment, over foresting/deforestation, waste dumping and producing poisonous waste too. Adding to an inbalance and saying it makes no difference is not a way forward.

Correcting dms172's siggy .... Guns dont kill people - people kill people (natures way of punishing the 'mighty' human race)

[Izzy]

I'm doing some on-the-side research for my science teacher, and Global Warming is one of the topics I'm looking into. This has got to be the shortest essay I've ever written, but it covers CO2. I'll eventually write another one to cover some of the other theories. Please pardon mistakes, it's late, I've just finished, and it hasn't been properly looked over yet.


Global warming is in no way a new thing. Throughout history, there have been periods of time when it has been a lot colder than it is now (the series of ice ages definitely being some of our foremost evidence, as we didn't have much documentation way back when), but also a lot warmer. During the Cenozoic era 65 million years ago (began when the dinosaurs died out, also the beginning of mammals), Earth was about 18° - 27° Fahrenheit hotter than it is now. Clearly humans weren't alive back then, so I can say without a doubt that this was not our fault. Earth's temperature shot up even further after this period, leveled off, went down for a while, we had a few ice ages, and now the temperature is rising again. (Details can be found here: http://math.ucr.edu/...z/temperature/)

There are many theories on what caused all this climate change, the Greenhouse Gas Effect most common among these. Greenhouse gases in the atmosphere make the atmosphere retain more of the heat from the sun, as it traps and re-directs the heat as it reflects back off the Earth. Contrary to common belief, green house gases are actually good for us. If we had no greenhouse gases in the air then we'd all be dead, because it'd be very, very, very cold. We are certainly putting more of these, CO2, SO2 and so on into the air, but the effect of that is dwarfed by the two main greenhouse gases, which are water vapor and methane. Though we have significantly added to the amount of methane through cattle ranches, flooded rice fields, and other things, all these gas emissions combined are still behind termites when it comes to the biggest producers of the stuff worldwide.

Human production of CO2 and SO2 also doesn't amount to much. A day, the average size volcano can emit anywhere from 20 tons to 10 million tons of S02, depending on volcanic activity, type, and the volume of magma involved. For example, the large explosive eruption of Mount Pinatubo on 15 June 1991 expelled 3-5 km3 of dacite magma and injected about 17 million tons of SO2 into the stratosphere. Along with this, volcanoes release more than 130 millions of tons of C02 into the atmosphere every year. Don't forget that there are thousands of volcanoes! C02 typically does not pose a direct hazard to life because it becomes diluted to low concentrations very quickly. But in certain circumstances, C02 may become concentrated at levels lethal to people, especially in volcanic areas where C02 emissions occur.

The point is, volcanoes and termites combined, in one year, produce way more SO2 and CO2 than the human race has in its entire history. Volcanoes came before us, volcanoes will stay pretty much long after we're gone. The planet is going to be fine pretty much fine whatever we do, but we stand some chance of wiping out a fair amount of life. So to conclude, it's mostly a natural process (heh, actually it's kind of arrogant to actually think we have so much affect on our planet), but we are doing something to make it worse, and being natural doesn't mean it'll be good for us.