According to measurements from Mauna Loa Observatory in Hawaii, with 410.31 ppm (parts per million), the level of carbon dioxide in Earth’s atmosphere hit a new high in April 2018. This is the highest point for the last 800,000 years.
Last year’s (April 2017) value, 409.00 ppm, was also a record high. As you can see in the graph below, which shows recent monthly mean carbon dioxide measured at Mauna Loa Observatory, Hawaii, it’s a continuing trend.
The highest level of atmospheric carbon dioxide reached in the 800,000 years
410.31 ppm is the highest level reached in 800,000 years. We are pretty sure about that: scientists have been studying gas bubbles trapped in glacial ice. By drilling more than 3 kilometers (1.86 miles) deep into the ice sheets over Greenland and Antarctica, scientists can see how temperature and atmospheric carbon-dioxide levels have changed since then. The air bubbles trapped in the ice can tell us the type of greenhouse gases (see notes 1) in the ancient atmosphere.
The ice may also contain dirt or other tiny particles that tell us when there were past volcanic eruptions. So, each ice core acts as an atmospheric time capsule. With the valuable information that they contain, scientists can compare the climate conditions of the past to today. By studying the climate of the past, scientists also can make predictions about the future. The last eight glacial cycles cover 800,000 years, and researchers are fairly confident that CO2 levels haven’t been higher than today’s levels in all that time.
In fact, the new record may hold even further back in history. A report published last year by the World Meteorological Organization revealed that 2016’s CO2 levels were higher than they’d ever been for at least the past three million years. And, in the following two years, we broke that record consecutively.
According to the report, the last time the Earth experienced a comparable concentration of CO2 was 3-5 million years ago, the temperature was 2-3°C warmer and the sea level was 10-20 meters (30-60 feet) higher than now. So, we can expect the oceans to rise substantially in the next 80-150 years. In fact, we already know that the global sea-level rise has been accelerating in recent decades. Say goodbye to Miami, Venice, and all coastal cities!
- A greenhouse gas is a gas in an atmosphere that absorbs and emits radiant energy within the thermal infrared range. This process is the fundamental cause of the greenhouse effect (the process by which radiation, from a planet’s atmosphere, warms the planet’s surface to a temperature above what it would be without its atmosphere). The primary greenhouse gases in Earth’s atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Without greenhouse gases, the average temperature of Earth’s surface would be about -18 °C (0 °F), rather than the present average of 15 °C (59 °F).
- “Trends in Atmospheric Carbon Dioxide” on National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory Global Monitoring Division website
- “CO2 Levels Have Reached a Scary New Milestone, But You’re Gonna Ignore It Anyway, Aren’t You” on Science Alert
- “Sorry Earth, Carbon Dioxide not this bad in 800,000 Years. Humans, 410 parts per million, nice job!” By Michael K. Spencer on Medium.com
- “Greenhouse gas concentrations surge to new record” on World Meteorological Organization webpage