Chart above based on ice core studies (climate proxies).
Estimated temperature range is about 12 degrees C.
We have already warmed about +10 degrees C.
from the cold peak glaciation period about 20,000 years ago -- and that warming has been very good news, unless you prefer Canada under ice.
I
prefer to say "over +5 degree C. warming", rather than +10 degrees C.
warming, to be more conservative -- climate proxies are not as accurate
as weather satellites.
It
is likely that we have already warmed +2 degrees C. since an unusually
cold period in the late 1600s and early 1700s that coincides with unusually low solar
output (aka Maunder Minimum).
That +2 degrees C. warming was also good news.
The "warmunists" claim that +2 degrees C. warming from the mid-1700s would cause a climate catastrophe.
That claim is a smarmy wild guess with no science backing it.
It is also a stupid claim -- +2 DEGREES C. WARMING HAS PROBABLY ALREADY HAPPENED SINCE 1700 !
And that + 2 degrees C. warming was GOOD NEWS.
The
warmunists appear
have no idea we've already had up to +2 degrees C. warming ... and people
loved it.
No that they care about climate history -- they are too busy using computer games to make scary (false) predictions of the future climate.
.
They've been doing this for 40 years and all we have to show for it are 40 years of grossly inaccurate predictions.
97% of computer game average temperature simulations overstate actual warming, often by a large amount.
100%
of computer game average temperature simulations missed the flat
average temperature trend between the El Nino warm years of 1998 and
2015/2016