Any source/data that backs that claim?
I assume you are referring to reducing GHG emissions, and would it reduce global warming.
There is lots of paleoclimatological evidence that shows correlations between increased atmospheric GHGs and increased global average temps, and decreased GHGs with decreased temps. In some cases some other factor triggered the initial warming or cooling, and GHGs acted as a positive feedback. For example, the cooling caused more snow and ice cover, reflecting more heat away from earth, and weathering draws down CO2 (see
dilu.bol.ucla.edu/home.html), but this is not balanced with GHG emissions, as the cooling reduces decomposition and traps methane in permafrost and ocean hydrates, reducing the atmospheric GHGs (methane stays in the atmosphere about 10 years & is a more potent GHG than CO2, but it degrades into CO2, which stays in the atmosphere a lot longer). The worst case of cooling was “Snowball Earth.”
The opposite occurs with warming. Whatever triggers initial warming (GHGs, or other factors), the warming melts the ice and snow, causing more heat to be absorbed, and also releasing methane from permafrost and hydrates, which cause more warming, causing more release, casusing more warming. Scientists cannot explain the extent of past great warming without including contributions of the greenhouse effect.
Some now say that the “methane shootgun” is more fully loaded than during the PETM great warming of 55 mill yrs ago, ready to respond to the initial warming we are causing; others point out it is not the methane, which only lasts 10 years, but the CO2 it degrades into which poses the more serious warming potential, some of which can last in the atmosphere up to 100,000 years.
So there is this correlation well into the past. And also a correlation with recent increased GHGs and the warming to date.
It might be good to start with a review of the discovery of the greenhouse effect nearly 200 years ago. At that time they came to realize that Earth was warmer than it should be, given its distance from the sun, and Venus a lot hotter, and Mars only slightly warmer, coming to understand it was due to the different levels of GHGs in their respective atmospheres. See:
en.wikipedia.org/wiki/Joseph_Fourier#Discovery_of_the_greenhouse_effect &
en.wikipedia.org/wiki/Svante_Arrhenius#Greenhouse_effect
Radiative physics explains how the GHGs create this heat imbalance, retaining more heat in our atmospher and earth systems. So it is more than just a correlation between GHGs and global temps, it is also based on the laws of physics.
Now you may be thinking there is no classical experiment which proves reducing GHGs will cause cooling (or stop the warming), and that is correct. We have to use the “natural experiements” as revealed by paleoclimatology for our understanding. We do not have two earths – on to emit extra GHGs, and one for the control. And it wouldn’t pass IRB approval to conduct such an experiment that endangers life on earth

And it is morally wrong to do a pretest-post-test experiment one earth – emit the GHGs and see if it actually does
Here is a site listing many sites that will explain it better than I:
realclimate.org/index.php/archives/2007/05/start-here/