How is 100 years of data enough to prove a trend when the earth has been around for much longer?

Question

How is 100 years of data enough to prove a trend when the earth has been around for much longer?

Answer 1

It's enough to show the impact man's emissions of CO2 have had.  Earlier data wouldn't really help, since CO2 levels were close to natural ones.

But earlier data can show the unusual nature of what's been going on:

http://www.globalwarmingart.com/wiki/Ima...

Answer 2

It must have been a heck of a sound bite, as they don't usually bother with any thing but the sound of their own ignorance.

Answer 3

Your preaching to the choir here.  On a planet whose weather cycles are measured in the BILLIONS of years, how can a few pencil necked air heads make their claims ?

What is even sadder, some actually believe them.

Answer 4

Your right, it's not. The latest cooling trend renders the alarmist's models worthless.

Answer 5

The nomenclature/label may have been around that long. I see(evans_mi), kept it short and sweet...just 2 decades of modern studies. That's it... the first ten had issues with orbital slippage, along with RSS feedback data. That has just been corrected in the last 2-5years? The only vantage the proponents have are the carbon isotopes. Less then 1.1%-c13-vs-99%-c12.  Start reducing these by producers in the natural environment.The percentage factors start declining rapidly as being a part of overall AGW, GHG's. You can always take their word, that CO2 produces heat, but nobody is going to believe that either. It's nothing more then a thermal retention factor as is other GHG's.

Answer 6

Exactly!! But we are never going to change the believers minds. The only thing that can do that is time. Sadly we will have to continue to listen to them drone on about their false claims while the world continues to do what it wants to do. It doesn't matter if we are having a colder than average winter up in the North.

I als love how they claim the Ice Caps are melting at an alarming rate. Well from what I saw this morning those Ice Caps up North of me are still frozen over and haven't started melting yet. Unless they somehow figured out how to melt when it's 20 below zero.

Answer 7

You can prove a trend with about 30 years of data.  The question is not whether there's a trend.  We know the planet is warming.

http://data.giss.nasa.gov/gistemp/graphs...

The question is whether this is a normal trend.  As summarized in the link below, scientists have determined that the current warming is different from past, natural climate changes.

Answer 8

you just need a long enough time frame to remove natural variability. you don't need to know temps for the whole history of the earth.

Answer 9

If you look at a small part of a chart, and then imagine that a small bump is the start of a big trend.......

    ,

Answer 10

Information about global temperatures is not only based on the last few recorded centuries. Scientists drill into ice layers in antarctica and the arctic circle and depending on the deepness know the years. They can measure air bubbles in the ice for CO2 levels, and derive the temperatures from that, and the way the ice froze on that particular layer depicting that period of time.

Answer 11

It isn't a matter of proving a trend, although the trend is there.  We have an increase of 30% in the level of CO2 in the atmosphere, caused by the burning of fossil fuels, and it is a piece of straightforward mathematical physics that this causes a 'greenhouse' warming effect.

Answer 12

It's not, and contrary to what others would like to imply, we do NOT have daily temperature readings beyond a dozen or so decades.

Edit:  Some people here continue to split hairs.  You CAN establish a trend line with a tiny amount of data.  What you CAN'T do is declare this trend "unprecedented" without first establishing the precedent.  Precedent can not be established by the same data claimed to be anomalous...and in this case, we have no other data.

Answer 13

scientist have much more than 100 years of data on earth. They have data from thousands and thousands of years ago obtained through carbon dating and uranium dating.

Answer 14

Have you ever considered that some people know more than you do about various subjects that they've studied and you haven't? This is one of them.