The world is still about 2oC cooler than the global average for the last 1 billion years, found through the analysis of sedimentary rock cores, & more recent values also from ice cores & tree ring samples, where we are still recovering from the last ice age in this current interglacial period where the polar ice caps formed a mere 33 million years a go.
140 million years a go during the most fertile era on this planet in terms of the explosion in the number and varieties of plant & animal life, CO2 was 3000 ppm. CO2 has gradually dropped since then from the locking of carbon in the formation of fossil fuels. Cellulite (wood) plants evolved about 140 million years a go & when the trees died there were no wood eating bugs, funguses or bacteria around to break them down (as there are now) which as they were buried under layers of rock through heat and pressure created coal seems. Sea custrations evolved to have a carbon based hard shell armour and depending upon conditions these locked up carbon as they died & decomposed to form oil & gas or just their hard shells survived to form calcium-carbonate or chalk.
With CO2 continually dropping over that last 140 million years we were about 2 million years from an ice age CO2 low point of it dropping below 120ppm (in the last ice age it dropped to 150ppm) so 85% species of C3 plants die out & planet B Earth so it then looks like planet A Mars. The other 15% are C4 plants that can survive with much lower CO2 levels but their photosynthesis requires much higher energy levels so they are limited to equatorial plants. The good news was humans by burning CO2 & raising CO2 are actually saving the planet until the politicians & anti-Westerners realised that Western civilization is build on a plentiful supply of cheap energy & those who control the energy supplies (politicians & governments, rather than the people through their businesses) control the people with their imaginary bogeyman clear, tasteless, inert, CO2 which is vital for plant life & our entire planet B Earth eco-system.
Stalin told us if you repeat a lie often enough people will believe it & virtually everybody in the Western world believe, including most on here, that rising CO2 levels are a problem & to be 'good' citizens we all need to work to reduce them. Religions, Communist & NAZIS et al all knew that if you want to brainwash a population, you start with the easily influenced & converted, the children, hence the children's globally coordinated school strikes today.
None of this is going to end well for the planet or Western societies.