In the 1950s, Claude Lorius answered an ad looking for young scientists to work in Antarctica as part of the International Geophysical Year. He returned year after year drilling ice cores to study ancient snow layers. One day in 1965 he was relaxing after work with a glass of whiskey poured over ice chipped from one of his ice cores. He noticed bubbles rising through the whiskey from the ice and had the eureka moment that ice cores trapped ancient air. He spent the next 20 years designing and testing techniques to extract ancient air from ice cores to measure the chemical composition of ancient atmospheres.
Lorius’ work led to the discovery that CO2 has varied over Earth’s history in concert with the Earth’s temperature and that today’s CO2 is higher than anytime in the last several hundred thousand years.
Claude Lorius recently died at the age of 91. He was part of a generation of climate scientists that began their careers curious about past climates. The more they learned, the more they began to suspect that current climate change is driven by human activity. Their work, the same work that showed the climate is always changing, uncovered the causes of past climate change and convinced the vast majority of the scientific community of the risk of human climate change.
> Lorius’ work led to the discovery that CO2 has varied over Earth’s history in concert with the Earth’s temperature and that today’s CO2 is higher than anytime in the last several hundred thousand years.
Then why isn’t the earth’s current temperature higher than at any point in the last several hundred thousand years? If I were a climate scientist and a global warming catastrophist I wouldn’t let this article see the light of day.
This doesn’t suggest causality and only hints any correlation.
Then why isn’t the earth’s current temperature higher than at any point in the last several hundred thousand years?
What temperature data are you using?
The science behind CO2 global warming is fairly simple, and can be shown in a classroom demonstration. No statistics needed, just common sense. I would put evidence on par with evidence that the Earth is not flat.
CO2 peaks in the OP graph: 0, 120, 250, 320, 400 thousand years ago.
Temperature peaks at 0, 120, 250, 320, 400 thousand years ago.
No scientist would say that. If they know the science. Well, they’d say it for a number of other reasons. A simple classroom demonstration vis a vis CO2 does not address complex systems and all that implies nor does it address all the contradictory evidence which of course will never be presented in a classroom because it busts the desired narrative. A simple classroom presentation does not address nor solve the problem but that mentality is itself one of the problems.
You are absolutely right, the ice core evidence doesn’t by itself show causality, just correlation. Other evidence shows causality. This distinction is important and, like many questions repeated by deniers, such as “is it the Sun”, or “is it just that the climate is always changing”, it is a crucial question. Your error is pretending climate scientists either don’t understand or are in a conspiracy to hide these questions. This is where the oil industry scientists come in. If mainstream climate scientists were so stupid to confuse correlation and causation then certainly the oil industry scientists would have noticed and disproved human caused climate change decades ago. But they didn’t, they agree that humans are causing dangerous climate change.
The answers to these questions are in the open scientific literature and detailed in IPCC reports. Here’s one paper on causality that concludes
Our study unambiguously shows one-way causality between the total Greenhouse Gases and GMTA (Global Mean Temperature Anomalies). Specifically, it is confirmed that the former, especially CO2, are the main causal drivers of the recent warming
