I am a physicist by education and work in industrial research so I consider myself at the same time able to understand the physical concepts underlying climate change and not an expert in any way. Because it is very important to say that experts in any scientific/research field are not clever minds that understand the basic theories by magic means, experts are the ones collecting data, working with them, knowing the research trends in the field and debating each other results. And scientific experts publish their work in peer reviewed journals. I have been lucky to publish scarcely in another area but not in climate, regrettably I think this also happens with some pretended “experts”.
But this time I want o walk a little bit by myself, because it is true that finally ones mind needs explanations understandable for himself. There are many evidences, this post from climateprogress is in may opinion quite clear about it, that something important is happening to the world climate, and it is happening fast in geological standards. Because it is not only about measuring temperatures in the land(a frequent sceptik criticism is about temperature measurement failures), it is also about sea level, glaciers, ice extent, sea temperature, extreme climate events,…
So, something is provoking that more energy is in our lower atmosphere, were we live. It could be the inputs, but solar cycles are in the same magnitudes as later centuries. There is no mayor volcano, no asteroid crash. But we are throwing tons and tons of greenhouse gases to the atmosphere and even if some continue having doubts, greenhouse effect was theorized and probed by Arrhenius 100 years ago. It is easy to explain in a simple way: we all emit radiation depending on our temperature, as the sun is much hotter than us its radiation is different from ours and some elements are able to stop suns radiation, whereas some others stop earths radiation like smoke hinders normal light propagation. This way if they stop our infrared radiation we will get hotter. It is the reason Venus is so hot, or the reason to the severe temperature difference between earth and the moon. And the more greenhouse gases the hotter we will get. Of course is more complex, feedbacks should not be forgotten and proven that our emissions are significant enough, but the main idea comes from the XIXth century, and the mechanism, the data and other measurements agree quite well:
If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck.