Manmade greenhouse warming would leave specific temperature differences at different altitudes in the atmosphere. We've looked for those differences and they aren't there. There is no manmade greenhouse warming.
The study cited in this article confirms earlier studies. There are also changes in the Earth's orbit that causes heating variability from the Sun.
Who are you citing for this information? One of the clearest signals that there is some warming occurring is that the stratosphere is cooling, as measured by satellites. The stratosphere is kept warm by longwave radiation from the lower atmospheric levels. If some of that radiation is blocked, which is what greenhouse gases do, then the stratosphere cools. And this is a very clear signal.