The denial is not about climate change, but about the
manmade up climate change. We know, for example, the peak of the most current glacial maximal period was about 18,000 year ago when sea level was 120 meters lower than today. By the time the man made up aspect for global warming and climate change appeared, in say 1860, natural global warming and natural climate change has already raised sea level by 119.3 meters. Yet the models do not give Mother Nature much credit as being a major contributing factor.
Below are two graphs of sea level as a function of time. I present it to show how nature has done this many times. On the bottom graph it shows the sea level has been rising since about 18,000 years ago. We are still in that warming cycle. The top graphs show mother nature has done this many times before, even over the past million years. This is natural to the earth, and since the earth and life is still here, this change is normal. There is no need to panic, kill the world economy and install global authoritarian socialism.
Man made climate change, even if true, is a unique occurrence in science. One occurrence of a theory is not enough to validate any theory. Isn't science supposed to run duplicate experiments before going to market and selling? As an analogous example of what I am saying, not long ago a team said they had a unique occurrence of cold fusion. Did we run with that, or was science acting more adult before drinking the kool-aid based on potential fame and fortune? Others were allowed to test and try to falsify the theory. No other team could duplicate that unique occurrence. Nature has many occurrences of global warming and climate change and is therefore the better theory in terms of following the rules of the philosophy of science. One can draw any graph through one occurrence point, including bogeyman scenarios.
Beyond that, the political side that is pushing man made up climate change are the Progressives, in general and the DNC in the USA. They are notorious for lying, running scams, money laundering tax payer money via their scams, applying political pressure, and now even law fair to silence opposition. The term denier sounds like one of the propaganda memes from their playbook. Denier is a derivative of same technique for calling someone racist, is they wish to discuss black on black crime in Democrat run cities. The goal is to silence opposition so the truth does not spoil their lies and coverups.
Water is the main variable for our earth's climate, not CO2. Water is the only material on earth that exists in three phases all at the same time and has the capacity to control climate. The proportion of these phases of water determine sea level and ice cover, as well as the amount of water in the atmosphere which then drives weather. Whether is about water vapor become liquid; rain, and solid; snow. Water is continuous from the atmosphere to the core of the earth and thereby impacts crustal plates and heat coming from the inner earth.
Water as ice reflects light and heat and adds a cooling effect to the earth, while water as liquid and gas absorb heat. The ratio of ice to surface water determines whether we get colder or warmer. Once the ice pack gets large enough there is run away cooling effect. The same is true as the ice cover melts to a certain surface area level, then we have a run away heating effect. If you look at the bottom graph at the upper left of the graph, sea level was already 10 meter higher than today and fell to the present level before Man made up, took credit.