The 'slight warming trend' as you put it, is, certainly, due to man-made CO2 emissions. This you have agreed to. How can you claim that reducing our emissions futile when you have admitted that our emissions have caused a raise in the mean temp anomaly?
I do not strongly agree that our emissions have caused a raise of some mean temperatures (not all and everything is warming on the globe by the way). I say it is not for sure what caused it.
It is too early to conclusively say that we have caused the current global warming trend basically, and to bite on 0,038% CO2 only. We still don't know all climate drive and change factors. There is a lot of research to be done still. It's not over. The mistake which some serious IPCC members also mention, was to be too much conclusively already, since the UN now considers to cut budgets for the IPCC.
What proof do you have saying that reducing emissions will have NO effect on the climate?
You really have to make a difference between will and might. I do not say it will have no effect. I say it might have no effect. Nobody knows what will happen exactly.
'Potential cause'? CO2 emissions in the only cause of above expected warming since man's industrialisation, as shown by scientific data.
What tells you that there are no different impacts? Yes, there is now 0,038% CO2 within the atmosphere. But the Earth's climate does not only depend on 0,038% CO2. There are a lot of more factors within the nature, but also the
solar system has to be considered. There is much research missing still...
'Reducing our emissions is the smartest and most appropriate course of action.
I agree. Reducing our emissions can't be wrong at all.
But it is also possible that such reductions do not show a significant impact. What if even the CO2 level would not really decrease significantly?
Remember that man-made CO2 emissions are only ~6% of all natural CO2 emissions. And I'm not yet convinced that we really know what happens exactly to all the CO2 contents within the nature. Science is not impeccable, less than ever climatology.