Claim: Without human intervention, the concentration of CO2 has climbed as high as 7,000 parts per million (ppm) in prior eras, whereas at present the concentration is just over 400 ppm.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: Global annual mean CO 2 concentration has increased by more than 45% since the start of the Industrial Revolution, from 280 ppm during the 10,000 years up to the mid-18th century to 415 ppm as of May 2019.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: Carbon dioxide in Earth's atmosphere is a trace gas, currently (mid 2018) having a global average concentration of 409 parts per million by volume (or 622 parts per million by mass).

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: The current concentration is about 0.04% (410 ppm) by volume, having risen from pre-industrial levels of 280 ppm.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: Human activities since the beginning of the Industrial Revolution (around 1750) have produced a 45% increase in the atmospheric concentration of carbon dioxide, from 280 ppm in 1750 to 415 ppm in 2019.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: CO 2 currently forms about 410 parts per million (ppm) of earth's atmosphere, compared to about 280 ppm in pre-industrial times, and billions of metric tons of CO 2 are emitted annually by burning of fossil fuels.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Since the time of the Industrial Revolution about 200 years ago, the concentration of carbon dioxide in the atmosphere has increased from about 280 parts per million to 370 parts per million, an increase of around 30%.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Human activities have caused CO 2 to increase above levels not seen in hundreds of thousands of years.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Measured atmospheric concentrations of carbon dioxide are currently 100 ppm higher than pre-industrial levels.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Atmospheric concentrations of anthropogenic (i.e., human-emitted) greenhouse gases have increased substantially.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: At very high concentrations (100 times atmospheric concentration, or greater), carbon dioxide can be toxic to animal life, so raising the concentration to 10,000 ppm (1%) or higher for several hours will eliminate pests such as whiteflies and spider mites in a greenhouse.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: While CO 2 absorption and release is always happening as a result of natural processes, the recent rise in CO 2 levels in the atmosphere is known to be mainly due to human (anthropogenic) activity.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Atmospheric CO2 has risen over the last 150 years to current levels of over 390 ppmv, from the 180 – 300 ppmv of the prior 800 thousand years This rise in temperature has reduced the Arctic ice cap to 1,100,000 sq mi (2,800,000 km2),[citation needed] smaller than ever recorded.