Tag: global warming

Global warming and me, part 2

[Go to part 1.]

I grew up in the 1980s, in Germany. Global warming caused by the burning of fossil fuels was getting attention in the press for the first time in a big way. The reporting was quite lurid — the announced “Klimakatastrophe” certainly was an attention-grabber — but the underlying scientific argument turned out to be simple enough for a teenager to grasp: The temperature of the earth surface is higher than it would be without the presence of certain components of the atmosphere, which cause the greenhouse effect (explanation skipped for the purposes of this post). The most important of these gasses is carbon dioxide. Burning carbon compounds that were buried underground a long time ago (many millions of years), humans add to the carbon dioxide that is naturally present, thereby increasing the greenhouse effect. By enough that the temperature on the earth surface should rise, on the average? Yes.

The next question that an interested mind would ask was “Can we see this temperature rise in measurements?” And back then, after some explanation regarding the difficulty to measure such a thing as a global average temperature, the answer was “Not yet: when we plot the curve, it trends upwards, but is still within the error bars. Come back in a few years.” (Error bars! Cool, I had just learnt about how to handle experimental error and uncertainty in maths and physics class!)

When in the early-mid 90s, I was working in a university lab, some of my friends worked in environmental physics, and their lab was right on the same floor. So I could ask them: what did they personally think? And the answer was unambiguous: Yeah, it’s going up. We expect it to go up theoretically, and it’s experimentally doing just that. They also warned that things would be a lot more messy than just a general warming at each location. We should prepare for more extreme weather — maybe some locations would get wetter or drier or even colder. It didn’t take long for these messages to move from my trusted scientific friends to official reports.

But global warming wasn’t the only or even the primary story about human activities harming the environment in pervasive and important ways that left an impression on my teenage mind. Not even close. Off the top of my head:

  • The ozone hole. Stratospheric ozone depletion over Antarctica was reported by a team of scientists from the British Antarctic Survey, in 1983.
  • Widespread damage to evergreen forests, most noticeably downwind from coal mining regions, dominated the environmental news in 1983 (and for a few years after that) under the keyword “Waldsterben” — the dying of the forests.
  • The Chernobyl nuclear incident happened on 26 April 1986. (I surprised my American/Canadian partner the other day by remembering the date.) It is hard to find a good single overview article on the web other than Wikipedia. For me and my peers this day marked the end of mushroom hunting and wild berry harvesting, and for weeks parents of my school friends checked out our school with Geiger counters.
  • The river Rhine, whose ecosystem was already known as severely damaged by industrial pollution, underwent multiple toxic spills, most prominently the release of large quantities of chemicals after a fire at the Sandoz agrochemical storage plant in November 1986.

I think it is the lessons I drew from how these and other events were handled and played out, then and over the years, that influence my attitudes now. A recent (and excellent) episode of the science podcast published by the journal Nature  looks back at the discovery of the ozone hole. One of the original authors of that first paper can be heard thus: “All of a sudden you look at it differently: Wow, we really can affect the planet as a whole.”

This statement on its own very much captures the main lesson, and it was new at the time. [The final part 3 is scheduled for May 21.]

Global warming and me, part 1

About a week ago, NOAA (the US National Oceanic and Atmospheric Administration) reported news from their longest-running atmospheric measurement station on top of Mauna Loa, Hawai’i: The average daily concentration of carbon dioxide in the atmosphere passed 400 parts per million (ppm) for the first time. This level was already reached a year ago in Barrow on the Alaskan north coast, and it is expected to take a few more years for global averages to rise to this number.

Mauna_Loa_Carbon_Dioxide_Apr2013.svg-1
Graph courtesy Wikipedia. Click to go to article.

The symbolic milestone led me to reflect on the messed-up state of the public debate on global warming and climate change, and its chances of moving into a saner state any time soon. I appreciate that people differ in their political attitudes and preferences about what actions should be taken, which I may agree or (strongly) disagree with. People may also pursue different goals, and that these may be in conflict between individuals. When it comes to discussing matters of fact, however, it should not be impossible to have a common ground on to lay them out and examine them, even if we end up drawing different conclusions or giving different weight to one over the other. Clearly, when it comes to the human impact on the earth’s climate and climate science in general this is very far from being the case.

When dealing with a scientific topic, only few people operate at the level of expertise to have a first-hand informed opinion on the current state of knowledge. Not that few, actually, but few compared to the size of the public as a whole. The rest of us rely on our general scientific background to evaluate what the specialist say, and on translators such as science writers, science educators and researchers from other disciplines to help fill gaps in understanding, link back to more basic knowledge and check that published results pass tests of plausibility. Another tool we use to figure out what factual statement we hold to be true is, I think, to be found in each individual’s biography: We build our mental model of how the world works incrementally. This is the case for judgements (what is important or not, what are the bases of my ethical guidelines etc.) just as much as for facts, and they intermingle. It is in this regard that I wonder about how the experience of the so-called denialists may contrast with mine.

Because it’s pretty much inconceivable to me how, having lived through similar times as myself, someone would end up believing that human activities are not causing changes to the global climate in a way that is worrisome. [Skip to part 2.]