Mark Lynas is a writer on climate change, and visiting fellow at the Alliance for Science at Cornell University. The opinions in this article belong to the author.

(CNN) To get the best view of current progress to tackle global warming, you need to climb a large volcano in Hawaii.

In the rarefied air atop the solidified lavas of Mauna Loa, more than 3,000 meters above the hubbub of modern civilization, sophisticated instruments hosted at the Mauna Loa Observatory take daily measurements of atmospheric CO2 concentrations.

Started in 1958 by Charles Keeling, the long-term output of these measurements is a graceful curve, which trends gradually upwards through recent decades. You can follow the Keeling Curve on Twitter -- earlier this year CO2 levels passed 410 parts per million, higher than at any time since the Pliocene , about three million years ago.

411.15 parts per million (ppm) CO2 in air 05-Jun-2018 https://t.co/MGD5CTru41 — Keeling_Curve (@Keeling_curve) June 6, 2018

The Keeling Curve is a reality check, because it shows not the slightest downward blip despite increasingly intense international efforts to restrain greenhouse gas emissions. Remember the 1997 Kyoto Protocol? You won't see it on the Keeling Curve. Nor will you find any sign of the Copenhagen Accord of 2009, or even the much-heralded Paris Agreement of 2015.

In other words -- despite all the noise and fanfare, the sleepless nights and long days suffered by delegates at the annual UN Climate Change Conferences (the Conference of Parties, or COPs), all the pledges on solar targets and coal peaking dates -- humanity hasn't yet done enough to make a tangible difference to the relentless accumulation of carbon dioxide in our planet's atmosphere.