Claim: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: Increases in atmospheric concentrations of CO 2 and other long-lived greenhouse gases such as methane, nitrous oxide and ozone have correspondingly strengthened their absorption and emission of infrared radiation, causing the rise in average global temperature since the mid-20th century.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: The spread of land plants is thought to have reduced CO 2 concentrations during the late Devonian, and plant activities as both sources and sinks of CO 2 have since been important in providing stabilising feedbacks.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: The seven sources of CO 2 from fossil fuel combustion are (with percentage contributions for 2000–2004): Carbon dioxide, methane, nitrous oxide (N 2O) and three groups of fluorinated gases (sulfur hexafluoride (SF 6), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs)) are the major anthropogenic greenhouse gases, and are regulated under the Kyoto Protocol international treaty, which came into force in 2005.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: Between the period 1970 to 2004, greenhouse gas emissions (measured in CO 2-equivalent) increased at an average rate of 1.6% per year, with CO 2 emissions from the use of fossil fuels growing at a rate of 1.9% per year.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: The sharp acceleration in CO 2 emissions since 2000 to more than a 3% increase per year (more than 2 ppm per year) from 1.1% per year during the 1990s is attributable to the lapse of formerly declining trends in carbon intensity of both developing and developed nations.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Along with the burning of coal, petroleum combustion may be the largest contributor to the increase in atmospheric CO. Atmospheric CO 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 , smaller than ever recorded.

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.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: The Arctic region is one of the many natural sources of the greenhouse gas methane.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Keeling’s Tellus article of 1960 presented the first monthly CO 2 records from Mauna Loa and Antarctica (1957 to 1960), finding a “distinct seasonal cycle…and possibly, a worldwide rise in CO2 from year to year.” By the 1970s, it was well established that the increase of atmospheric carbon dioxide was ongoing and due to anthropogenic emissions.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Climate change can increase atmospheric methane levels by increasing methane production in natural ecosystems, forming a Climate change feedback.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: High-latitude tundra and boreal forests are particularly at risk of climate change-induced

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: As a result of this feedback process, “BC on snow warms the planet about three times more than an equal forcing of CO.” When black carbon concentrations in the Arctic increase during the winter and spring due to Arctic Haze, surface temperatures increase by 0.5 °C.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: The Woods Hole Research Center, citing two 2015 studies on permafrost carbon says there may be a self-reinforcing tipping point where an estimated equivalent of 205 gigatons of carbon dioxide in the form of methane could cause up to 0.5 °C (up to 0.9 °F) warming by the end of the century, which would trigger more warming.