evidence: The amount of planet-warming carbon dioxide in the Earth’s atmosphere has hit a new record, as humanity struggles to rein in emissions of greenhouse gasses from burning fossil fuels. [...] This May, the concentration of CO2 in the atmosphere hit nearly 427 parts per million, which is an increase of about 3 parts per million compared to last year’s peak. That’s one of the largest annual jumps on record, scientists say. [...] The amount of carbon dioxide in the atmosphere has been steadily increasing since scientists began routine measurements in 1958. At that time, the CO2 concentration in the atmosphere was 313 parts per million, slightly higher than in the 19th century, when the Industrial Revolution sparked the widespread consumption of fossil fuels.