how would you know if global warming was human induced.?

Question

if you dont have an oppinion of your own please dont send me a link.

thanx dana for not adding 8 links and taking up the whole page.

Answer 1

The only reason some think global warming is cause by man is because they use flawed logic.

Man creates co2 = co2 is a greenhouse gas = Man causes warming.

Then all efforts are made to disprove all other sources of warmth to narrow and focus only on the man made part.

Answer 2

There are three steps in the argument. The first is to demonstrate that there is global warming by looking at what is going on around us. You can check for yourself the reduction in the size of glaciers in different parts of the world and so on. For me there is a significant reduction in the length of the winter and the amount of frost but to show that this is a global issue you need to look at some graphs.
The second part of the argument is to show that it is unlikely to have been caused by the warming that is going on naturally. We know that we are in a period following an ice age and the world was warming up anyway. But if you look at the graphs you see that there was a change about 1950 which only became apparent a few years later. Since then the trend has been strongly upwards much faster that previously observed.
The third part of the argument is the most likely cause is an increase in so-called greenhouse gases. To maintain the same temperature the earth has to radiate back to space the same amount of energy which false on it. The theory is that the greenhouse gases slow down the amount of energy being radiated back.
No scientific hypothesis is ever finally proved. They are disproved or they remain provisional At thsi stage most climate scientists, not all, believe what is going on is best explained by the greenhouse gas theory.

Hope this helps.

Answer 3

I know it the same way Admiral Truly does:

"I wasn’t convinced by a person or any interest group—it was the data that got me. I was utterly convinced of this connection between the burning of fossil fuels and climate change. And I was convinced that if we didn’t do something about this, we would be in deep trouble.”

Vice Admiral Richard H. Truly, USN (Ret.)
Former NASA Administrator, Shuttle Astronaut and the first Commander of the Naval Space Command

But the data is way too long for a Yahoo answer. So you have this problem:

No links, no data, no knowledge.

Answer 4

I am 68 years old and I have watched places that I lived in 30 or 40 years ago, have an average temp 10 to 12 degrees warmer than when I lived there because of all the CONCRETE and STEEL and HOUSES and CONDOS...

Answer 5

There are many basic scientific facts which can only be explained if the current global warming is being caused by an increased greenhouse effect due to carbon dioxide accumulating in the atmosphere from humans burning fossil fuels.

http://answers.yahoo.com/question/index;_ylt=As6MMc8lLk5ZrMSOAhywS77sy6IX;_ylv=3?qid=20071215102828AAxyWW6

Basically we know it's warming, and we've measured how much:

http://www.ncdc.noaa.gov/img/climate/research/2005/ann/global-blended-temp-pg.gif

Scientists have a good idea how the Sun and the Earth's natural cycles and volcanoes and all those natural effects change the global climate, so they've gone back and checked to see if they could be responsible for the current global warming. What they found is:

Over the past 30 years, all solar effects on the global climate have been in the direction of (slight) cooling, not warming. This is during a very rapid period of global warming.

http://news.bbc.co.uk/2/hi/uk_news/6290228.stm
http://www.pubs.royalsoc.ac.uk/media/proceedings_a/rspa20071880.pdf

So the Sun certainly isn't a large factor in the current warming. They've also looked at natural cycles, and found that we should be in the middle of a cooling period right now.

"An often-cited 1980 study by Imbrie and Imbrie determined that 'Ignoring anthropogenic and other possible sources of variation acting at frequencies higher than one cycle per 19,000 years, this model predicts that the long-term cooling trend which began some 6,000 years ago will continue for the next 23,000 years.'"

http://en.wikipedia.org/wiki/Milankovitch_cycle

So it's definitely not the Earth's natural cycles. They looked at volcanoes, and found that

a) volcanoes cause more global cooling than warming, because the particles they emit block sunlight

b) humans emit over 150 times more CO2 than volcanoes annually

http://volcano.und.edu/vwdocs/Gases/man.html
So it's certainly not due to volcanoes. Then they looked at human greenhouse gas emissions. We know how much atmospheric CO2 concentrations have increased over the past 50 years:

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

And we know from isotope ratios that this increase is due entirely to human emissions from burning fossil fuels. We know how much of a greenhouse effect these gases like carbon dioxide have, and the increase we've seen is enough to have caused almost all of the warming we've seen over the past 30 years (about 80-90%). You can see a model of the various factors over the past century here:

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

This is enough evidence to convince almost all climate scientists that humans are the primary cause of the current global warming.

Answer 6

Simple. Look at the scienctific findings.

Of course, this requires actually learning something about science and taking the trouble to do some reading. A deplorably large number of people aren't willing to do that. Which, I suppose, explains the "deniers" (sigh).

Answer 7

Being only a backyard scientist, I would never claim climate change was caused by humans. Especially when I know this isn't a new thing that our planet is experiencing.