How can Al Gore claim ANYTHING? Polar bears still exist, and Planet Earth is still floating in space.
There is no “climate denial”. Everybody agrees there is climate, and that climate does, in fact change over time. The point of contention is not the climate can and does change, it is WHY.
And carbon dioxide, at whatever concentration in the atmosphere, has such a minuscule effect it may be dismissed as none at all. Water vapor is a MUCH more powerful factor in the rate and scope of climate change. And it is from thirty to well over a hundred times the concentration in the atmosphere as carbon dioxide.
This is relatively simple scientific knowledge, and only those who are being willfully ignorant could ever assert otherwise.