There's overwhelming evidence supporting the claim that climate change is real. The intention of this guide is to list out all such known evidence.
There's a rising consensus in the scientific community that climate change is real and caused by human activity. 97% of climate scientists support this argument (more about this).
People who deny climate change have their own motivations but once you look at the evidence, it helps in understanding the situation better and empowers you to educate others.
What this guide is not about
This guide is not about -
Countering arguments that skeptics may have against the evidence (we'll cover those in another guide).
How to stop global warming (deserves a dedicated guide of it's own).
Evidence 1 : Increase in Carbon Dioxide levels.
Carbon dioxide is a greenhouse gas. This means it is heat trapping in nature and higher levels of it in the atmosphere would cause the planet to warm up more than it should.
The amount of carbon dioxide in the atmosphere has never been more than 300 parts per million in hundreds of thousands of years - until the mid of last century. Since 1950, this level has been crossed and it's growing linearly every year.
The direct measurement of the same, made since 2005 till now is represented in the following graph -
How do we know what amount of Carbon dioxide was present in the atmosphere hundreds of thousands of years ago?
We do this by studying ice cores. These are cylinders of ice that has been freezing layer over layer for millennia. By studying the inner depths of the ice core, scientists can estimate what the atmosphere would have been like.
Apart from specific data backed evidence, there are many other compelling signs indicating that climate change is real. Here's a list of those -
Decreasing Snow Cover
The northern hemisphere is loosing snow cover rapidly since the last five decades. Learn more here.
Measurements suggest that the surface oceans have become 30 percent more acidic since the mid of last century (industrial revolution). This is a great threat for the aquatic ecosystem. Learn more here.