I am thankful that I live on a planet where the air is breathable and protects us from gamma rays, X-rays and cosmic particles. And water exists as vapor, liquid and ice and a lot is drinkable.
And that while we benefit from the nearly unlimited sources of fossil fuels which give many of us easy and convenient power, transportation and lighting and communication, many people have realized that it is possible to achieve the same results without drastically changing the chemistry of our atmosphere and oceans byusing solar and wind power, among other sources.
And that I live in an era where genocide, ecocide, racism and rigid class distinctions are no longer seen as normal or acceptable, and that there are still organizations devoted to saving our atmosphere, our oceans, and fighting against oppression of some people by others.
I am also thankful that science has advanced to the point that our satellites have visited all of the official planets in our solar system, as well as many of the minor objects, and have also discovered thousands of planets orbiting other stars. Let me point out that so far, every single one of those other planets that astronomers have been able to measure appears to be a different version of hell. If we discover another planet that is in fact habitable in the way that our Earth is, it will be so far away that (as far as I can tell) there is never going to be any way for any humans ever to visit it. So, if we screw up Earth and turn it into a Hell, there is no escape. We must guard it with all we got.
Last but not least, let me add that I am truly thankful that I have a loving family and friends.