Or at least there shouldn't be.
Science is very imperfect (does this really need to be stated?). Scientists are people. People are fallible, and people are quadruple fallible in groups.
In the face of an avalanche of information, history has shown over, and over, and over again that people have a tendency to essentially select data that fits the narrative, and to grossly overestimate the confidence of one's understanding of complex systems (we're seeing this already as the model of global warming veers wildly from what is actually happening with the world. This model was used, with high confidence, to pitch massive economic restructuring world-wide, but it has become evident that we as a species know less about how to model a world climate system than we imagine).
As someone else pointed out, this very submission has the egregious mistake that it compares granular data with 350-year smoothed data (which itself is taken from derived sources) -- being in the financial industry, I've seen countless cases where such shenanigans are used for very fraudulent purposes, but this is science because it fits the accepted narrative.
I'm not a "climate change denier", as an aside, though it's unfortunate that some cannot rationally reply to anything without such absolutism. I am naturally skeptical, however.
Granted, science is imperfect and all too human. I'd even go so far as to argue that it's deficient, dysfunctional, and perhaps even somewhat defective. But its products are orders of magnitude more credible than some random scientific-context-free graph by someone with no scientific reputation on the line. Most scientists have decades of experience and plenty to lose if it turns out they were sloppy or selective. By contrast, those doing anti-AGW advocacy can do "drive-by" FUD: they can use dirty data tricks because they don't need to convince a scientific community, there are negligible reputational consequences if they're wrong or they deliberately mislead, and their funding is secure regardless because either they're unfunded or it comes from murky or agenda-heavy sources rather than from competitive science grants.
What can be infuriating is when people equate drive-by FUD with, e.g., the products of the IPCC. This is tantamount to rejecting the entire scientific enterprise.