For example, the graph of CO2 concentration takes center stage. Fine, have a look at the caption:

> Atmospheric carbon dioxide concentrations in parts per million (ppm) for the past 800,000 years, based on EPICA (ice core) data. The peaks and valleys in carbon dioxide levels track the coming and going of ice ages (low carbon dioxide) and warmer interglacials (higher levels). Throughout these cycles, atmospheric carbon dioxide was never higher than 300 ppm; in 2018, it reached 407.4 ppm (black dot). NOAA Climate.gov, based on EPICA Dome C data (Lüthi, D., et al., 2008) provided by NOAA NCEI Paleoclimatology Program.

So this is all ice core data, apparently. Except that the study was done in 2008. Yet there's a point clearly marked 2018 average in bold. Where did it come from?

I could assume that it came from atmospheric monitoring, but that's not what the site says.

Not good. Probably not ethical. When data from different sources are mixed together, but not identified clearly as having different sources, that's dishonest at best. And I see it all the time in the public presentation of this research.

Let's set aside the issue of whether anthropogenic climate change is real or not. I'm talking about presenting data to try to convince a general audience that something is true.

What I've seen so far is lacking.

This just documents increase in atmospheric CO2 since 1970 and theories about what effects it might have. It completely leaves out the temperature changes in the 20th century and how there were warming and cooling periods despite steady increase in CO2, which quite obviously means there are stronger mechanisms involved (if there was cooling despite CO2 increase in the 60s/70s).

> It completely leaves out the temperature changes in the 20th century and how there were warming and cooling periods despite steady increase in CO2, which quite obviously means there are stronger mechanisms involved (if there was cooling despite CO2 increase in the 60s/70s).

The second graph shows that the warming/cooling is seasonal and that the overall trend has been up, in-line with CO2 levels. I don't understand what you don't understand about the second graph (your question is confusing, aside from explaining how seasons work on earth).

The second graph shows no temperatures at all, it's CO2 ppm / year.

> the overall trend has been up, in-line with CO2 levels.

That's simply not true. If you have more than a decade of cooling with steady increase of CO2 and recently more than a decade of steady temperatures with sharp increase of CO2, it's obvious that there are other factors involved.

> I don't understand what you don't understand about the second graph

You should take a closer look at it.