I found several articles which claim mans contribution to greenhouse gases is between 0.5 and 5% depending on?

Question

weather or not water vapour is beeing taken into account. Also recently in the artic the highes ammount of snow and ice since records started have been measured.
What does that tell us, that mans impact on the enviroment isnt as big as we thought, or that mans contribution, depsite beeing small in % when compared, is enough to have a major impact on the enviroment, to the point of raising the sea level ?

Answer 1

It's true that percentagewise, human greenhouse gas emissions are small as compared to the natural carbon cycle. However, the natural carbon cycle is well-balanced. Take a look at these diagrams of the carbon cycle:

http://en.wikipedia.org/wiki/Image:Carbon_cycle_diagram.jpg
http://www.whrc.org/carbon/

While humans are emitting a relatively small amount of carbon, it's more than the natural cycle can absorb, so it gets stuck in the atmosphere. Slowly it continues to accumulate up there, increasing the greenhouse effect and thus increasing global warming, as you can see here:

http://en.wikipedia.org/wiki/Image:Climate_Change_Attribution.png

Answer 2

Climate models generally make some rudimentary assumptions about the composition of the atmosphere, percentages of water vapor, CO2 etc.., but they are not sophisticated enough to model clouds, so they are generally are ignored. Clouds have a huge effect on climate based primarily on capturing heat via radiative processes and by shielding the surface from solar radiation. Convection is also a very important process in earths atmosphere for dissipating from the surface to the upper troposphere that is completely beyond the capabilities of climate models.

There are so many positive and negative feed back systems in our weather and climate system that it will be many years before computing power and software development will allow for us to truly understand the nature of things.

One very simple principle that is often overlooked, is rain, and it's importance to the carbon cycle. Every time a raindrop falls through the atmosphere, it takes a small amount of CO2 from the atmosphere and forms a very weak acid rain. When the rain falls on rocks with calcium the carbonic acid dissolves a tiny amount of the calcium, which end up in the ocean. Tiny plankton use both the carbonic acid and calcium carbonate in their shells, the very building blocks of all life on Earth. CO2 is the gas of life, just as much as oxygen is.

Answer 3

Just because someone publishes a scientific paper, is it accurate? Likewise the same with the answers forum. Just because I write an answer here does that mean that it is accurate?

There is an organisation that the name escapes me, that I believe the UN founded, that have a consensus of scientists working on papers in this field. The results from memory were opposing.

When you get 'science' giving two sets of figures, then we start managing risk. Another thing to consider is the intrinsic interest and pressure from companies to continue using the same fuels.

I mean don't some cigarette companies still refute the link between lung cancer and cigarettes and at one stage advised cigarettes were 'in fact good for you'. A packet of cigarettes a day keeps the doctor away.

I guess an easier way of putting it is having Iran and North Korea with a high number of nuclear arms, and the USA invading both, If someone presses the button and the technology works, the results are devastating.

USA and Australia are saying that the risk of wasting money is higher than the risk of destroying the planet.

Answer 4

Can you add links to the articles then I can go through them and explain them in more detail. I suspect that the figures may have been massaged to suit the stance adopted by the particular publications.

Information from neutral sources puts the proportion of man's contribution to present global warming at upwards of 80%. This figure can easily be distorted by the omission of certain facts. It's true to say that man has contributed less than 0.001% to global warming but this is in respect of the age of the planet.

Figures of between 0.5 and 5% would suggest that they're taking the whole of the current global warming phase which spans the last 18,000 years. For 17,800 years the warming has been natural.

As for increased snowfall in the Arctic. This is one of the many consequences of climate change and has been predicted and observed for quite some time.

As the planet warms there is greater evapouration of water from the seas and oceans, this leads to increased precipitation. A trend that has been ongoing for some time and is set to continue. In warm places this falls as rain, in cold places it falls as snow.

Unfortunately some skeptics try to hoodwink you by pointing out there has been more snow in the Arctic or that mountain glaciers are growing. In doing so they're providing further evidence that global warming is happening. In the Arctic and high in the mountains it's exceptionally cold, any increase in snow or galcial mass results from increased snowfall which can only come from increased evapouration from the seas and oceans which can only happen if the planet warms up.

Answer 5

no, more like 30% for CO2, 50% for methane, and 100% for others. Your using emissions data, which is misleading because it is not atmospheric concentration. Nature takes back the amount it gives off and some of the amount human activity gives off too. so 2.5% of that 5% is taken back by nature, and the other 2.5% of all emissions is the amount that builds up, every year 2.5%, every second 2.5%, it starts to add up.

Answer 6

You need to cite those articles so that others can look them up to see if thearticles are credible or not.

There has been a great deal of material printed regarding the Global Warming issue that is not credible.

Just because someone printed something somewhere does not make it credible.

Answer 7

All greenhouse gases combined only make up 1% of the atmosphere.. yet they account for about 40% of our heat retention. So it only takes a small amount of change to be felt.

as far as the snows in some places.. that is extreme weather (global warming affects weather, but it is not weather), and was actually predicted in the super computer models of global warming.

Answer 8

They're counting water vapor. Because it rapidly exchanges between the air and liquid water, it has a very short "residence time" in the atmosphere compared to CO2.

That means, while water vapor helps keep the Earth warm, it cannot cause an _increase_ in temperature by itself. If there's no other cause for warming, if more water gets into the air, it falls out as rain. It cannot "force" climate change.

CO2 has a very long residence time (years) which means it can and does cause increasing temperature.

An important detail is that the warmer air can hold more water vapor, which increases the temperature more. This is a "feedback" effect of global warming.

Bottom line. Water vapor is the largest greenhouse gas. But it can't cause warming by itself. It can (and does) make other warming worse.

More here:

http://environment.newscientist.com/channel/earth/climate-change/dn11652

Just another "logical", but wrong, argument from those who deny global warming. Scientists know it's nonsense, which is why they agree global warming is real and mostly caused by us.

Good websites for more info:

http://profend.com/global-warming/
http://www.ucsusa.org/global_warming/science/
http://www.realclimate.org
"climate science from climate scientists"

Answer 9

On the increase in snowfall in the arctic, that happens anytime there is an increase in evaporation at the equator. Combined with the melting, the result is smaller, thicker ice caps in the short term.

Answer 10

Those figures--whic are not exactly correct, but close enough--have been touted by the "skeptics" as "evidence" that mandoes not have animpact on global temeratures. All they've done is demonstrate their own ignorance.

Here's why. Under normal circumstances, Earth' atmosphere, ocean temperatures--the whole "system" is in a state of equilibrium--like a see-saw balanced with equal weights at both ends. That equilibruium changes naturally over time, of course--but only very slowly, over periods of thousands or tens of thousands of years.

Butit doesn't take much to "tip" a system out of equilibrium. again, using the see-saw analogy, adding just a few ounces of weight to one end can tip the see-saw out of balance, even though the added weight is only a tiny percentage of the total weight on the see saw.

That's what's happening. A small increase in the CO2 content adds a small but signifigant "blanket" holding in heat--and that's enough to start a series of major climate changes, as well as melting of glaciers and polar ice.