What are three observations that scientists interpreted ad evidence for global warming?

Question

What are three observations that scientists interpreted ad evidence for global warming?

Answer 1

Rising CO2 levels observed directly since the late 1950's.

Air bubbles in ice cores that trace climate back 800,000 years.

Stable isotope analyses that can differentiate the proportion of CO2 in the atmosphere released from natural biological sources and from anthropogenic CO2 from burning fossil fuels.

Answer 2

Rising CO2 levels

Rising Temperatures

Less CO2 absorption by the oceans

Others include

Isotopic Ratios of past climates

Hotter summers

Longer Droughts

Warmer winters

Less Snow Cover

Melting Ice Caps

Sea Level Rise

Glacier Mass Loss

Rising levels of other Greenhouse Gases like Methane and Nitrogen Dioxide.....

I could go on for days

Answer 3

Some of the above answers are wrong.  Everybody assumes that global warming always reads “man-made global warming”.  That is the way we have all been brainwashed by recent events.

The incidence of rising greenhouse gases in the atmosphere, is not in itself an indication of global warming – you have to show conclusively that the rise in GH gases has caused global warming.  The connection has been shown with computer modelling, but in the field, there are many instances that show otherwise.

The way actual global temperatures are measures is now through satellite readings across the world and average ocean temperatures taken across the world.  Historical temperatures are deduced from tree rings and ice cores.  

These did indeed indicate that the global temperature was rising until 1998.  From 1998 to 2006 it levelled, and from 2007 to the present it has dropped dramatically, against all the models put out by the IPCC.  

Please do not confuse man-made global warming with global warming.  Global warming and cooling has been going on as long as Earth has existed.