Climate change is an unprecedented global challenge. The magnitude of the problem and the consequences of inaction can be overwhelming, but there is still time to act.
I spend a lot of time thinking about climate change. It’s both an issue that I care deeply about, and part of my job. A component of my work at the Xerces Society is to understand how climate change can affect invertebrates and the ecosystems they inhabit, and to figure out ways that we can incorporate climate change into our habitat work—especially here in California’s Central Valley, where I live.
Our core strategy for improving pollinator resilience to climate change is two-fold: protect, restore and enhance quality pollinator habitat; and increase habitat connectivity. Protecting, restoring, and enhancing habitat means that pollinator populations can be larger and therefore better able to survive bad years or extreme weather events. Increasing habitat connectivity also allows pollinator populations to be larger, but has the additional benefits of increasing gene flow and facilitating the range shifts that are expected with climate change. Here in the Central Valley, we’re working with farmers, managers of roadsides and natural areas, and people in cities and towns to create pollinator habitat.
The past several months have seen publication of many important new research studies, which have been reported in the media. Although sometimes I suspect that the reason I see so many climate change stories in my news feed is simply because those are the stories I click on, recent polling shows that 66% of Americans believe action on climate change is warranted, and encouragingly, news coverage is beginning to reflect that attitude. So, let’s talk about a couple of the climate change stories that have made it into my news feed (and hopefully yours), and what these developments mean for invertebrate conservation.
In October 2018, the Intergovernmental Panel on Climate Change (an international body made up of scientists from around the globe), released a special report on the effects of 1.5° Celsius of global warming, and how those effects compare to 2°C warming. Let’s start with what, exactly, that means: 1.5°C (2.7° Fahrenheit) is referring to the increase in average global temperature since the start of the industrial revolution, when humans began burning fossil fuels at a large scale. The average global temperature is measured by averaging the temperature all around the planet, from the Sahara Desert to Antarctica. Human activities (primarily the burning of fossil fuels, but also deforestation) have already warmed the planet 1°C (1.8°F) above preindustrial levels. The stated goal of the Paris Agreement is to keep warming below 2°C (3.6°F), with a preferred target of 1.5°C (2.7°F). However, current pledges made by countries to reduce carbon emissions are not sufficient, and will lead to warming of 3°C by 2100. A difference of 1 or 2 degrees may seem small, but it is actually very big—because, again, this is a change in the average global temperature, not local temperature. For comparison, the difference in average global temperature between a warm period and an ice age is only 4°C to 6°C (7.2°F to 10.8°F).
The IPCC report discusses the many economic, social, and ecological effects we can expect with 1.5°C warming, and also explains how keeping warming to 1.5°C versus 2°C (or higher), can minimize some of the worst effects of climate change. For example, at 1.5°C warming, 6% of all insects are expected to lose 50% of their range. This is important because a smaller range means smaller populations, which are much more vulnerable to extinction. (Xerces blog readers are also likely aware that insects represent over half of all described species, so 6% of all insects represents a large chunk of global biodiversity.) But at 2°C warming, 18% of insects will lose at least half of their range, and at 3.2°C warming, 49%.
This report serves as a call to action, outlining how keeping warming to 1.5°C instead of 2°C will enable us to avoid the worst effects of climate change, while also giving us more time to adapt and more flexibility in choosing mitigation strategies. The second significant thing this report does is provide a timeframe for action. Holding warming to 1.5°C is possible—but we have to act quickly and boldly. To keep warming to 1.5°C, we must reduce greenhouse gas emissions 45% by 2030 (20% by 2030 to achieve 2°C warming), and cut emissions to zero by 2050 (by 2075 for 2°C warming). Again, this is possible, and the report outlines some ways to achieve this goal. It will require political will at all levels of government.
We also know that loss of insects will lead to declines in many other animals. A new study showing large declines in arthropod abundances in Puerto Rico was published the same month as the IPCC report. This study joins a growing list of long-term research showing worrying declines in insect abundance and diversity. Apart from the alarming decline in arthropods observed, there are two things that stand out about this study. First, while other studies of arthropod declines usually point to habitat loss and pesticides as major culprits, the authors were able to rule out those causes and show that climate change is the most likely cause of this dramatic decline in arthropods. Second, and important, they also show how these declines cascaded through the food web, with similar declines found in insectivorous birds, frogs, and lizards. So not only does this study document dramatic impacts of climate change on invertebrate populations, it reminds us of how important insects are to supporting a diverse food web and maintaining healthy ecosystems.
Part of meeting emissions targets involves employing strategies to reduce the amount of carbon in the atmosphere. While new technologies that do this efficiently may yet be developed, the most effective means of sequestering carbon from the atmosphere is still provided by healthy ecosystems. Ecosystems such as forests, grasslands, and seagrass beds, along with well-managed croplands and grazing lands, serve as carbon sinks, sequestering carbon from the atmosphere. Forests are especially valuable—think of trees as giant sponges, soaking up carbon from the atmosphere during photosynthesis, and storing it for decades or centuries. Protecting natural habitat, reforestation, and good management of working lands are all part of natural climate solutions to mitigate climate change. This is hopeful news, because research shows these natural climate solutions can make substantial contributions towards emissions reductions necessary to keep warming to 1.5°C.
The Xerces Society’s work to create pollinator and other insect habitat, as well as our work with farmers to improve soil health (healthy soils sequester lots of carbon) with cover crops and similar practices, can help to mitigate climate change as part of a natural climate solution. So far, we have restored and protected over two million acres across the U.S. for insects. Climate resiliency has become a primary consideration in the Xerces Society’s design of habitat. We need habitat systems that can persist in the face of pressures such as increasing frequency of drought (most urgently, in the West), the increasing frequency of storm damage in the Southeast and Mid-Atlantic, and the rising variability in temperatures and precipitation in the Midwest. Ensuring that new habitats are made up of plants that will readily establish and survive under future conditions will ensure these habitats both provide for wildlife and capture carbon.
Climate change is an unprecedented global challenge. The magnitude of the problem and the consequences of inaction can be overwhelming, but there is still time to act. While the federal government is rolling back some of the progress that has been made in reducing carbon emissions, many cities, states, and businesses around the country remain committed to climate action. We can build on this momentum and support further action.
Although climate change is a global issue, it is also vital that we all focus locally to protect and restore habitat. You can help your neighborhood pollinators to be more climate resilient by planting pesticide-free gardens, with a variety of native flowering plants. See our pollinator garden tips and our many publications for science-based advice on how to get started, or build upon the foundations you have already established.