This year my daughter Emma Woolliams, a metrologist who works with climate change scientists, has given a good few online lectures and I had the good fortune to be virtually present at two of them. I and 15 people from Maryland were at the first one, back in June, her American friend Laura (an Associate Professor of Environmental Studies and Sustainability) hosting that meeting. At the end, one of the students in Laura's class paid Emma a compliment, saying "This has been one of the greatest hours I've ever spent thinking about climate change!"
Emma began her talk by quoting the 'Apollo 8' astronauts who'd said "We went to the moon and we discovered the Earth." When the photos were published the realisation also dawned for others that no political borders are visible from up there, and that our earth is fragile and precious.
The science of climate change starts with light, she said, describing her youthful enthusiasm for exploring light-waves. The earth is a thermal body, emitting at wavelengths that we can't see. Infrared cameras in satellites look at this part of the spectrum, detecting the heat radiated from earth. Its temperature is stable when the energy taken in = the energy given out. Visible and "near infrared" light from the sun can easily penetrate the
atmosphere; it's the infrared radiation not getting out again that
causes the warming.
99.9% of the earth's atmosphere is composed of nitrogen, oxygen and argon. If that were 100%, then a stable temperature of -18°C could be maintained, as on the moon. For more warmth on earth we need the "greenhouse effect". H2O, CO2 and methane molecules vibrate in the atmosphere when the thermal radiation excites them, thus balancing earth's temperature. Water is the most prominent of these greenhouse gases. Warmer air holds more water, which makes more energy, causing more / bigger storms. The planet seems to breathe, its temperature rising and falling.
The super-computers used by meteorologists analyse atmospheric models, and from these models, predictions can be made. The Global Observation System — thousands of computers working together — processes the data concerning the Essential Climate Variables (ECVs) measured from satellites, from balloons, from weather stations, by robots in the oceans, and so on. She mentioned masts erected in the Namibian desert that measure the reflectance of the ground and the transmittance of the atmosphere. Emma and her colleagues can use such data (and from sensors elsewhere on the earth's surface) to check the performance of the Earth Observation Satellites. She also showed us pictures of a device monitoring the leafy canopy in Oxfordshire woodlands.
Satellite cameras themselves are sophisticated enough to detect the Leaf Area Index (LAI) of our planet's forests and allow scientists to draw conclusions about the ocean water from measuring its colour, affected by the amount of phytoplankton, sediments and so on. Half of the CO2 in the ocean is absorbed by phytoplankton floating in it. (The rest is absorbed by the water itself and acidity monitors on buoys can measure that.) The satellites observe changing sea levels, too, and can even provide supportive information in disaster relief situations.
We're seeing retreating glaciers, the destruction of coral reefs. The reduction in sea ice is closely watched; a 2° rise in temperature would submerge some of the world's populated islands.
From 8000 BCE to around 1900 the earth had a fairly stable climate. Things have changed since then. The evidence of man-made global warming is overwhelming.
She said it was time for feminist thinking. Men prefer to tackle one thing at a time. Women are more capable of considering lots of input together. Humanity is making progress and partnerships are crucial. Since the United Nations created its Sustainable Development Goals, every country on earth is making progress towards them. Emma quoted her heroines, Mary Robinson and Christiana Figueres, both of whom have injected "stubborn optimism" into the climate change conversation, and she spoke of Project Drawdown, which suggests 100 solutions for lowering the carbon dioxide we emit. Because of Covid-19, people are beginning to think locally and globally rather than nationally. We have been obliged to listen to scientists this year; it's a good habit to acquire.
Emma left her audience with the words Courage - Hope - Trust - Solidarity.
For the Environment Action meeting I hosted in Ottawa on October 19th, I had asked if Emma would repeat this presentation. To my delight she was very willing to do so, but she added and subtracted some slides, to suit the audience I'd mustered. We had 29 participants at this first guest-speaker meeting on our program, mostly CFUW people, though we had a couple of extra people along as well.
Again, Emma stated that global atmospheric models predict an increase in temperature. She said that islands were bound to disappear and it would be better if their inhabitants would be able to leave with dignity than as helpless refugees, so the world should start thinking about how to manage this. She also mentioned people who currently live on mainland coasts and near rivers. Many will be displaced. Canada is likely to become one of the havens for climate refugees, and with warming temperatures, this country could become as the food basket of the world.
She described how governments are competing in their pledges to achieve 'net zero' carbon by the mid-century. Can it be done? There was a fall in CO2 emissions during Covid shutdowns, worth noting. Again, she mentioned Project Drawdown and the 100 solutions that could save us. We need to get organised to tackle our problems; the effectiveness of our action depends upon whom we can influence.
Scientific observations play a crucial role in finding ways forward, being powerful motivators for change. Measurements ensure that everyone can see the impact of global warming. Metrology fixes the broken links in the chain of information, she said. Again, she listed the different kinds of metrology taking place around the world — satellites, radar, planes, weather stations, etc., all contributing. Emma's own job is to look at composite measurements, correcting for differences between measurements past and present, and to calibrate new satellites before they are launched. She also chairs a European Metrology Network whose purpose is collaboration between scientists and between these scientists and the "stakeholders" with whom they communicate.