I would expect anyone interested in climate science to start his studies by investigating what causes the biggest known changes in climate -- the ice ages.
Why should anyone care about what causes tiny changes in average temperature -- tenths of a degree C. -- over decades, or centuries?
Those are tiny changes no one would ever notice, if not for smarmy leftists (falsely) bellowing climate change will end life on Earth as we know it ... in their 50+ year effort to scare people about the environment ... which allows them to take more control over people and their businesses (the primary goal of leftists).
A review of what scientists think causes ice ages finds no consensus.
If scientists can't agree on what causes the ice ages, then much more work needs to be done to answer that question.
Answering the question of why Earth's average temperature is slightly warmer than it was in 1850, assuming you believe the very haphazard measurements, is mainly a waste of time.
Who cares?
Earth's climate is always warming or cooling -- minor changes don't matter -- it's the big changes that could hurt us.
Reconstructing past ice ages using information from ice cores, deep sea sediments, fossils, landforms, etc.:
(1) Data show ice ages tend to develop slowly, but end more abruptly.
(2) Global temperatures fluctuate often, and rapidly -- there were many large, abrupt climate changes over the past 100,000 years.
(3) Within the short time span of a few decades, or a few years, global temperatures are believed to have changed by as much as 15°F (8°C) or more.
A warming trend was interrupted 12,800 years ago when temperatures dropped dramatically in only several decades.
1,300 years later, temperatures spiked as much as 20°F (11°C) within a few years.
Sudden changes like this happened at least a few dozen times during the past 100,000 years.
Are these climate proxy studies accurate?
That's worth debating.
What caused the sudden large changes in temperature?
Not coal power plants.
Not SUVs.
Probably not CO2 since it seems to rise AFTER the temperature rises, per ice core studies (I assume oceans warming from non-CO2 causes, later release CO2).
Given how poorly existing climate models have performed when predicting the future climate, and the fact they are based on CO2 as the "climate controller", which is an unproven assumption, it should not be a tough job to discredit existing climate models.
If you assume the satellite data are accurate, I wonder why so much of the warming since 1979 was in the northern half of the Northern Hemisphere, and so little was in the southern half of the Southern Hemisphere?
My only theory is surface albedo changes, in the Arctic only, from dark soot constantly dumped on the snow and ice from burning a lot of coal and wood in the Northern Hemisphere, especially in China
Unlike climate modelers, I admit my dark soot in the Arctic theory could be wrong, and will not character attack anyone who disagrees.