As more than 190 nations meet in Paris this week to build an alliance aimed at keeping the global average temperature from rising more than 3.6 degrees Fahrenheit compared with pre-industrial levels, there is great optimism that the worst effects of a warming climate can be avoided.
As the Earth’s temperature rises, increases in the Valley’s minimum nighttime temperature, maximum daytime temperature and daily average temperature over the annual cycle will affect agricultural crops, air pollution, worker productivity, electricity demand and many other aspects of our lives, ecosystems and economy.
Together, increases in temperature and shifts in precipitation will affect water storage, inter-annual availability of water for agriculture and cities, groundwater withdrawals, drought incidence, evaporative demand across the landscape, wildfire incidence and extent, wildlife habitat and more.
Extreme heat several days in succession affects outdoor workers, particularly in agriculture. Public health is affected by the impacts of warming on air quality, food production, the amount and quality of water supplies, energy pricing and availability and the spread of infectious diseases.
For example, warmer temperatures affect ozone production, as well as smoke from wildfires. Both have known health impacts. These impacts fall especially hard on the low-income, rural populations characteristic of the Valley, owing to the lower level of capacity to cope with and adapt to the impacts of warming.
Many impacts of climate change on the Valley will be felt through changes in the water cycle. These start in the Sierra Nevada, with snow and rain shifts and earlier snowmelt. These changes affect water availability in storage for use during annual and multiyear dry periods.
Further effects in the region will be noticed through groundwater depletion and quality; they also affect land subsidence.
The 21st Conference of Parties (COP21), also known as the Paris Climate Conference, builds on 20 years of negotiations aimed at achieving a legally binding and universal agreement on climate, with the goal of keeping global warming below 3.6 degrees F.
This process started with the Rio Earth Summit in 1992, when nations adopted a “Framework on Climate Change” aimed at stabilizing atmospheric concentrations of greenhouse gases to avoid “dangerous anthropogenic interference with the climate system.”
Yet it is now clear that the ambitious – but voluntary – reductions in greenhouse gas emissions pledged by nations in the weeks before COP21 won’t be enough to prevent global warming that is disruptive to our economy and society in California and across the world.
The Paris Climate Conference will make progress, but much more will remain to be done.
California can lead the way to a more secure global future, and the Valley will realize economic and social gains by being part of that leadership. As we continue switching from a fossil-fuel economy to one based on renewable energy, we will see continued job growth, better air quality and a healthier environment.
California has set targets for reducing greenhouse gas emissions and increasing the amount of energy generated from renewable sources. The Central Valley-Sierra Nevada region is an excellent site for more renewable energy, and its agricultural/forest byproducts can be tapped as feed stocks for renewable, sustainable bio-gas and/or electricity production.
These steps toward carbon neutrality for the state will create economic opportunities and jobs, just as California's environmental programs have in the past helped create jobs and spur investment in clean technologies.
The University of California has pledged to achieve carbon neutrality on its 10 campuses by 2025. At the recent UC Carbon and Climate Neutrality Summit, we released a report on “Ten Scalable Solutions for Carbon Neutrality and Climate Stability” as a practical road map for other parts of the world to follow. That road map is being distributed at COP21.
The UC also has joined the Breakthrough Energy Coalition, an influential group of investors, led by Bill Gates, that is committed to investing in technology that can help solve the urgent energy and climate challenges facing the planet.
Together, we must all take the measures that will avoid the worst impacts of climate change, and we must adapt to what we cannot prevent. Both are priorities for our region and state. We must do both for the sake of our children and future generations.
And in doing so we can chart a more sustainable future for the region.
Roger Bales is a hydrologist and a distinguished professor of engineering at the University of California, Merced. He is also the director of the Sierra Nevada Research Institute and a member of UC President Janet Napolitano’s Global Climate Leadership Council.