Suffice it to say that a 2oC temperature rise would pose an unacceptable risk to our civilization and most of the world ecosystems. That seems quite a dramatic claim, but there is pretty good certainty that the heat input involved in that 2oC temperature change would be sufficient to melt global ice, raise the sea level and cause uncertainty enough to risk, alter, damage, or destroy 80-90% of the investment in real estate, infrastructure, agriculture and organization that humanity has made to date. It will also mean a mass extinction of species and climate chaos. By “climate chaos” I mean the occurrence of storms, droughts, high temperatures, low temperatures, rainfall, hail stone size, and tornado size that are “unprecedented” and can’t be managed by historical hazard mitigation measures.
I wanted to make this personal by considering the history of CO2 emissions against the human scale of seven generations of my family. As an engineer, I don’t think of safety limits as “targets.” Failure to reduce fossil fuel production to nearly zero in my lifetime will mean unacceptable hardship for people I know. So how did we get to this point?
Here is my family:
- Great Grandmother Agnes – She died before I was married, but I remember her well. The last member of my family denied the right to vote by law.
- Grandmother Ruth – She died when my daughter was 10 years old, so we remember her well. She lived through the Great Depression and World War II.
- Mother Sue – Still enjoying retirement from public education. She married an Air Force enlistee during the Vietnam War, but she has never had a child or grandchild involved in armed conflict.
- Me – I have passed 50 years old, and I am the first woman to be promoted to full professor in engineering by my university.
- Daughter Kierra – Has finished university and a couple of big OE’s and into her career in environmental law.
- Granddaughter – No definite plans yet, but she’s coming!
- Great granddaughter – It is conceivable that I would know her.
When Agnes was born, there was a global warming safety margin of nearly 2300 GtCO2, and the global emissions were about 0.3 Gt/yr. So, my Great Grandmother Agnes would have not been worried about the way that her society's energy use might affect her great granddaughter (me). She would have been much more worried about what life would be like for herself and her daughter: would they get the right to vote, have legal protection, attend university in sciences, and survive wars, depression and even famine? She and her husband lost their farm in the Dust Bowl environmental disaster in the 1930’s when my Grandmother Ruth was 4 years old. Her son fought in World War II.
When my mother was born, the world was in ruins from war, the family lived in a tiny two-room house, the children had two outfits per year, and mothers knew how to make a small amount of food stretch to feed a whole family. But the 1950’s were just around the corner, and the trends for just about every graph of every type of consumption or production were just about to rocket upward.
When I was born, the CO2 emission rate was up to a happy 4.6 GtCO2/yr, and the safety margin was still over 2000 GtCO2. When I was born, climate scientists were already measuring the atmospheric CO2 level at Mauna Loa and could see it rising exponentially, echoing all of those other exponential trends. If the fossil fuel production rate had been frozen at 1963 levels back then, due to alarm over exponential growth of emissions, then the safety margin would not have been exceeded for another 385 years, in the 2350’s! More importantly, the safety limit of 350ppm causing climate change would have been more than a century away. No wonder nobody was worrying about climate change when I was a baby. When I was in university 20 years later, I was protesting nuclear weapons, mad levels of military spending, and environmental destruction. But, I did decide to study Mechanical Engineering because I was concerned about energy and global warming. I wanted to work on renewable energy. Interestingly, about 91% of all historical CO2 emissions have been emitted during my lifetime, since 1960.
When my daughter Kierra was born in 1989, CO2 emissions were up to 13.2 GtCO2 per year and the safety margin had shrunk to less than 2000 GtCO2. The Berlin Wall had just come down and the Cold War was negotiated to a stand-off. The risks and imperatives of fossil fuel emissions reduction were simply known and not debated. This is the era where the Kyoto Protocol was established. It was understood that continued growth of CO2 emissions was presenting a risk. The idea was to ensure the annual emissions stayed around these levels of 13.2 Gt CO2 from 2012 onward. The safety margin would have run out in 80 years at this rate of emissions. That's still just one lifetime, but it was thought that within that time new technologies would be developed to reduce emissions while fuelling continued growth. This is the era where people changed status from “citizens” to “consumers”. This is the era where we started talking about our “needs” and “hungers” for cheap energy to maintain our lavish lifestyles. Needless to say, there was no green energy revolution.
In 2012, Kierra turned 23 years old and started to think about a family, and the emissions level was 31 GtCO2 per year. So now, if the nations of the world woke up and actually limited fossil fuel extraction to the 2012 levels – no more growth – then within my lifetime, about the time my daughter is retiring, and my granddaughter is finishing her PhD, the climate failure limit will have been exceeded. I will live to see what climate chaos looks like. I will get to observe the failure modes of a planetary thermodynamic system forced out of balance.
With about 1500 GtCO2 cumulative emissions to the failure limit remaining, at current fossil fuel production rates, the failure limit will be reached in 36 years. By my calculations, if all the people of the world agreed on radical reduction of 15% in fossil fuel production per year for the next 10 years, so that fossil fuel production rate would be around level it was when I was a child...then the climate failure limit of 2oC would not be reached at the end of my great granddaughter’s lifetime. However, the limit recently agreed on at the COP21 meeting in Paris of pursuing efforts to stay below 1.5oC will have been exceeded.
My challenge as a Mechanical Engineering academic is to take on the work of transition. I can work with students to envision the prospect of the world reducing fossil fuel production and consumption drastically, to one tenth of current levels, starting now. I can think about how difficult that would be, how much hardship people would experience in using 15% less fuel next year. The oil shocks of the 1970’s had only about a 7% drop in oil consumption in one year. I can wonder about the meaning of “hardship” for people now, when I think about the hardships of my grandmother Ruth and great grandmother Agnes. I can develop methods to plan for the transition to 90% less fossil fuel. And I can teach these methods and write a text book and start an organization of professional engineers who work on transition of all kinds of systems to use 90% less fossil fuel. And still when my great granddaughter is my age, she will likely have to face climate issues with coastal cities, extinction of species, unprecedented droughts, floods, temperatures and storms. This is because the safety margin is already exceeded. The climate is already changing.
There are actually two reasons to dramatically reduce fossil fuel production: the climate failure limit as already discussed, and the fact that even a small amount of fossil fuel is necessary for the essential benefits of industrial society. Engineers in my granddaughter’s and great granddaughter’s time will make things work – but their jobs will be impossible without a model amount of high-quality fuel. I realise that the idea of dramatically reducing fossil fuel production is unthinkable to most people my age. I have talked to some retired people my mother’s age about reduced and curtailed fossil fuel production. They have not been receptive to the idea. I have talked to young people my daughter’s age about reducing their travel and consumption and driving, and they have not been receptive to the idea. “We need the energy for our economy,” they say. This need for energy is only one generation old. Out of all the thousands of generations of people who have lived, one, mine, will live their entire lives as profligate users of fossil fuels.
Have human societies been this un-mindful of their own future, and that of their children, grandchildren and great grandchildren, at any time in our history? Especially in the world’s advanced economies, might my generation and my parents’ generation become willing to sacrifice some of our conveniences and some of our vacations, drive our big cars about half as much, and buy less stuff that will end up in landfills? Is that sacrifice so unthinkable that our grandchildren are going to have to experience climate chaos?
Right now, if I imagine my future granddaughter and I think about what she will need, what I realize is that the only solution that makes any sense for her is for us to wind down dramatically the extraction and production of fossil fuels. If we do this, then we will have to use existing resources wisely to change all of our industrial production, transportation and end use and use dramatically less fossil fuels. If we succeed at this, then we will provide justly for the needs of future generations.
Hansen, J., M. Sato, P. Kharecha, D. Beerling et al. “Target Atmospheric CO2: Where Should Humanity Aim?” Open Atmospheric Science Journal 2 (2008): 217-31. http://www.iiasa.ac.at/