"Many believe that us humans are causing temperatures to raise. Do you think it's not true?"

In a word YES!

http://www.frot.co.nz/design/sift/global-warming/

Here in New Zealand it's colder and the glaciers are growing each year... (Of course that is being covered up - but I have seen them myself a decade apart and know it to be the case)

And how are the sea levels? - Like many Kiwi's I live on the coast - the water levels haven't changed much, but going on some hundred year old photos there is just slightly more land above water now - the exact opposite of what the propaganda media claims