Tag Archives: Anthropocene

Adiós, ancient coastal cities

Global sea level rise has long been a predicted consequence of global warming, as massive ice sheets at the poles and on mountaintops pour their melted water into the sea. (Pumping groundwater out of aquifers and onto land (which then ultimately drains into the sea) is also a culprit.) Coastal cities are already bearing the brunt of sea level rise, from aquifer incursion (making water too saline to use) to overwhelming sea walls and stormwater infrastructure.

Sea level rise is a growing threat to one of the oldest European settlements in North America. Founded by Spanish settlers in 1565, St. Augustine FL is now struggling to protect its heritage sites in the midst of profound state-level denial and delay. The likelihood of the city surviving another 450 years seem very slim. Of course, it isn’t helpful that these challenges are often overlooked in academic circles; a recent call for papers for an Urban Heritage conference has no mention of the impacts of climate change on ancient coastal cities, even though the majority of urban populations live along coastlines. Urban heritage preservation in the face of climate change impacts (floods, droughts, intense weather events, and others) will be an important area of work in the decades ahead.

Goodbye glaciers

The US-IALE conference in Anchorage was short but sweet — great science, wonderful colleagues, and new ideas.

However, as picturesque as the setting was, it was deeply unnerving. This winter was one of the warmest on record for Alaska, and indeed for much of the past winter, Alaska was warmer than much of the eastern US. When I arrived in Anchorage, it was at least 20 degrees (F) warmer than Houghton had been, and the trees were already fully leafed-out and blooming. Several wildfires contributed to a haze around the city that marred views and made our clothes smell like a campfire; the fire season started early and is expected to be a severe one, thanks to warm weather and dry conditions in the forests.

My son and I went on a glacier tour…. truly impressive! The blue hues and striations of black sediment made them far more beautiful than I had imagined. As we watched one of the glaciers calving, I wondered if any of those glaciers would be around for my son to show his children; odds are against it. Many speakers at the conference spoke of the difficulty that our “no analog” future presents us when we try to develop management plans for our ecosystems more than a few decades out. While they were talking about the vast reorganization of species and ecosystems that we are likely to see, I thought about how I might describe things like glaciers and tundra to my grandkids….. I am certain that my words, and even my photos, won’t do them justice.

National Climate Assessment rolling out now

Ignore the beautiful but dysfunctional interactive website, and instead go straight to downloading the highlights  or the full report. The documents are a treasure trove of data, documenting all of the changes in our climate that we have already witnessed and what is likely to come. The report offers data and projections by region, sector, and response strategies.

The price of gold and the loss of forests

“Everything is connected” is something we say so often in ecology that it often loses its meaning. However, this new study published today in the Proceedings of the National Academy of Sciences really exemplifies the real world impact of these connections.

Skyrocketing gold prices, driven mainly by speculators, has spurred an epidemic of illegal mining (and consequently deforestation) in the Peruvian Amazon. These mines are dangerously close to a major river system, increasing the risk of mining pollution entering the Madre de Dios River watershed. Mining and deforestation often go together, as we know very well here in the UP.

Greg Asner and his colleagues used remote sensing imagery to detect these mines and measure deforestation caused by them. The images themselves provide a powerful message. Each hectare lost to mining can support hundreds of tree species, and thousands of animal species which depend upon them. The loss of these forests and risks of pollution are difficult to calculate, and therefore difficult to balance against the fluctuating value of the gold retrieved from the mines.

30 years in the blink of an eye

Time, NASA, USGS and Google have joined forces to create a stunning tool to visualize the extensive change that has occurred on our planet at human hands. Dubbed “Timelapse“, millions of Landsat satellite images from the past 30 years have been joined to allow the user to pan across a landscape and witness deforestation in the Amazon, glacial retreat from climate change, tar sands mining in Alberta, mountaintop removal in West Virginia, and urban sprawl in cities like Shanghai, China and Las Vegas, New Mexico (with the accompanying water withdrawal from Lake Mead).

It is often difficult for us to conceptualize and understand the scale at which our natural resource and land use reconfigures our world, but this tool helps immensely. Take a few minutes to check it out……

All of this has happened before

Although summers are quite busy, usually I try to find the time to read several books that have been occupying the corner of my desk during the academic year. I have finally read a book on my “meaning to get to” list for years: “Prehistoric Native Americans and Ecological Change,” (Cambridge University Press), by the professors who taught me landscape ecology, Paul and Hazel Delcourt.

Originally published in 2004, the book combines archaeology and paleoecology to describe how landscapes in North America were changed by human societies long before Europeans arrived. Ecologists especially have always believed that pre-European societies had little lasting impact on ecosystems in North America. This belief underpins many conservation biology targets for habitat and species restoration. However, the Delcourts describe thriving human societies in Ontario, southern Illinois and Eastern Tennessee that used fire and forest harvesting to support their agriculture-based societies, dramatically increasing nut-bearing trees and pioneer species (such as ragweed) at the expense of species adapted to mature forests. These changes, made at increasingly large scales, may have also increased herbivore species such as white-tailed deer that thrive in early-successional and edge woodland habitats.

The book is framed by Panarchy theory, and explains how these changes, when they reached a critical proportion of the surrounding landscape, created greater disturbances (such as floods) that likely led to the area being abandoned by these societies, long before Europeans arrived on the scene. These events are a reminder that humans, like all species, alter their environments. Sometimes these alterations are beneficial in the short term, but often they are detrimental in the long term. Even with small-scale disturbances (such as slash-and-burn agriculture), if the period allowed for ecosystem regeneration is too short, soil fertility can decline and ultimately the practice becomes unsustainable.

Of course, the lessons we gain from the distant past (14,000 to 500 years before present) are limited in their applicability. North America is now home to over 400 million people, almost two orders of magnitude larger than it has ever supported before. It may be that the agricultural and settlement practices of even the most sustainable of these early societies would be completely unsustainable today. But what we can learn is that our impacts will certainly be available for study for a long, long time.

The Anthropocene epoch

There is an interesting piece in this week’s Science regarding the discussions that geologists are having at their meeting this week, as to whether the epoch we are in right now should be officially called the “Anthropocene”, and if so, when it should start.

It may seem like one of those nerd debates that doesn’t really matter to normal folks, but this one really does. The article has some excellent graphics and truly frightening statistics to anchor this debate. Consider this: 80% of the Earths’ land area has been altered by humans, and 90% of the biomass represented by mammalian species is currently tied up in either human or domesticated livestock bodies. Think about that…. our bodies and our cows, goats and sheep outweigh all of the lions and tigers and bears out there, not to mention the elephants, whales, and gorillas.

Wow. That one took me a while to process.

So what does this say about our future on this planet, or even the future of our planet? Back in 1986, Peter Vitousek* sounded an alarm regarding our increasingly heavy footprint, estimating that humans soaked up about 40% of the planet’s Net Primary Productivity, a measure of how much sunlight plants convert into biomass. That doesn’t leave much left for the millions of species with which we share this rock. And unfortunately, our fate is tied up with most of those millions; if they go, there is no guarantee that we won’t go too.

*Vitousek P, Ehrlich P, Ehrlich A, Matson P. 1986. Human appropriation of the products of photosynthesis. BioScience 36:368-373.