Climate Change Resources

We must preserve a critical refuge among changing climate forces.

Photo: Courtesy Hawk Mountain Sanctuary

Climate Change Today and Tomorrow

After three decades of temperatures marching steadily upward, the evidence of profound alterations in our planet’s functions are everywhere.  Altered storm and drought patterns have been widely reported; now new evidence documents that the very distribution of cloud cover across the globe has shifted. The higher temperatures and new precipitation trends are affecting forests, streams, and wildlife including those here in our region.  The timing of bird, insect, and plant life cycles is changing, coldwater streams are becoming too warm to support native wildlife, mountaintop ecosystems are increasingly stressed, and a variety of species in Pennsylvania, as elsewhere, are shifting northward, upslope, upstream or to deeper depths in response to rising temperatures.  By the end of this century, it will be much harder to find our state bird and our state tree in the Commonwealth of Pennsylvania.

Climate change is introducing new uncertainty into the conservation work of wildlife agencies, foresters, and fisheries managers in our state.  Are the best management practices for protecting resources in relatively stable times the right practices to use in times of increasing change?  And, if species are likely to move north or to higher elevations, do we need to find new places to protect?  How does the Kittatinny Ridge fit in to climate action?

How Climate Change Affects Our Forests and Wildlife

Two early victims of climate change in Pennsylvania are the hemlock forests and trout streams.  Trout and other coldwater species suffer directly from the warming of the climate, while the hemlocks and associated species are declining as a result of a warming-enabled invasive pest. In both cases, the effects are spreading relentlessly, and are expected to become pervasive in our lifetimes.



For decades, the stately hemlock forests of Pennsylvania have been under attack from a small, easily overlooked insect, the wooly adelgid.  Much like the aphids which are the bane of many summer gardens, the adelgid literally sucks the vitality out of infested host plants.  Over time, infested hemlock trees weaken, suffer branch die back and, eventually, die.

Until quite recently, wooly adelgid populations were kept in check by hard cold spells during the winter months.  As winter temperatures have gotten milder, the pest is expanding northward.  It is now found in all counties along the Kittatinny Ridge and most counties in Pennsylvania.

Stricken trees die over a period of about five years, as the life is sucked out of them. As the hemlock groves succumb, other species that depend upon a hemlock ecosystem will also decline.  When the hemlock forests are gone, we will find we have also lost colorful summer songbirds such as the Blackburnian warbler, black-throated green warbler, and blue-headed vireo. Many reaches of coldwater streams will also be adversely impacted by the loss of critical shade from the hemlock canopy.

Want to investigate what the future may hold for the hemlock pest, the wooly adelgid?  Look for data on winter low temperatures.  Warming trends in winter lows and declines in the number of days with lows below freezing are the climate variables to track.  On the Climate Explorer website, you can request projections for your county to see what trends are being forecast on these indicators.



One of the most climate vulnerable species in Pennsylvania is a favorite of anglers.  The eastern brook trout is unable to tolerate warming stream temperatures, and rapid losses in populations have been reported during times of thermal stress. Warming air temperatures in future years are projected to significantly reduce the current range of the species as more stream temperatures reach lethal levels for these fish and other coldwater species.

Pockets of native trout may persist in certain stream reaches, generally those receiving sufficient volumes of cool groundwater to keep base flows up and in-stream  temperatures low. However, many streams in the Kittatinny corridor will experience depopulation of cold water species and the pockets of survivors that do remain may be at risk from their growing physical and genetic  isolation.

The effects which warming air temperatures have on stream temperatures can often be mitigated by maintaining forested buffers along the stream banks.  Researchers have found in-stream temperatures in Pennsylvania as much as 3° F cooler where forested buffers exist.  However, other factors sometimes overwhelm the capacity of forested buffers to fully moderate temperature swings.  Upstream conditions, elevation, and flow volumes also influence the temperatures experienced in any given stream segment.

Looking for more information on the brook trout?  You’ll have to look hard for good news on the climate front.  EPA’s dire assessment estimates near total losses of the fish by the end of the century, while the Eastern Brook Trout Joint Venture projects a few pockets will remain, but perhaps not along the Kittatinny. Other research which notes climate change as the largest threat to the brook trout, identifies summer high temperatures presenting the major threat, especially to small fry and egg survival.

Brook Trout
Brook Trout, Trout Unlimited



Interested in more information on the ruffed grouse and other climate-sensitive birds?  National Audubon has dynamic range maps of the most sensitive Pennsylvania species, projecting how bird populations will shift over the next 50 years.  The data on the ruffed grouse suggest that changes in summer climate conditions will have the greatest impact on this species, but other bird species’ responses vary.

Ruffed Grouse

Ruffed Grouse

The Kittatinny As A Climate Refuge

Biodiversity conservation practices are being re-examined to assess how well approaches used in the past will work under changing conditions in the future. Trying to restore ecosystems to historic conditions may no longer make sense or have a lasting impact. But if conservation cannot rely upon its old goals and objectives, what do the new objectives look like?

Even the ability to identify where to make conservation investments is receiving scrutiny. Conservation professionals, faced with many moving targets, are challenged to identify climate ‘refugia’ where species have the best chances of survival in the face of climate change. And, in this discourse, our region has begun to attract attention. Increasingly, scientists are looking at the Kittatinny Ridge as one of those crucial climate refugia that will support climate resiliency for a variety of plant and animal communities.

What is climate resilience?  It is the ability to withstand, or recover from, the stresses created by climate change, and it varies from one species to another. Since each  species has its own climate sensitivity and adaptive abilities, how can a place like the Kittatinny Ridge be recognized as a climate refuge?

The key features of the Kittatinny that make it a regionally significant climate refuge include:

  • Biodiversity – the region supports a variety of species and ecosystem types already
  • Topography – the region’s landscape encompasses variations in elevation, shading, and other drivers of microclimate diversity that provide a ‘stage’ for different ecosystem types
  • Habitat connectivity – the natural landscape is relatively unfragmented, allowing species to move to new areas if their current location becomes inhospitable.

The Kittatinny, and the Appalachians more broadly, provide all these attributes making them a highly  important refuge and corridor for eastern ecosystems.

Kittatinny Conservation: A Climate Change Strategy

Large, continuous stretches of unfragmented forests and unobstructed, free flowing streams are valued for the ecological benefits they provide in sustaining healthy ecosystems today.  These unbroken stretches of lands and waters are even more essential when working to ensure climate change resilience over a long time horizon. Many species are going to shift their ranges to the north, to higher elevations, and to pockets of cooler waters. It is unclear how quickly these range migrations will happen and how far species will travel as they adjust. One thing we can be confident of is the need for natural spaces to allow range migrations to occur.  And we can help by protecting large contiguous corridors of natural lands and waters in which species can adapt.

Conserving an intact Kittatinny Ridge is now being viewed as a critical conservation strategy for the sustainability of future wildlife populations, forest communities and headwater streams. The intact, connected ridge landscape stands apart from surrounding lowlands where human alteration of the landscape is the norm. Its lasting protection from encroachment and development is needed to avert  future losses of wildlife. Safeguarding the forest and stream connectivity of the Kittatinny needs to be more widely recognized as a central tenet to long-term stewardship of our region’s natural resources.

In some ways, the conservation playbook for climate change is much the same as it has been when it comes to land conservation and waterway protection: protect critical habitats permanently and use limited resources strategically to get the greatest benefit.  What is new is the even greater importance now being ascribed to connectivity.  The new pre-eminence of connectivity must become a central part of our region’s ethos. The Ridge’s connectivity is a scarce and vulnerable asset; we need to cherish and safeguard that connectivity.

Want More?

Here are more resources with information on climate change and things we can do to address it.


Climate Change on the Kittatinny
Kittatinny Climate Change Strategy
Connectivity Planning
Enhancing Municipal Tree Cover
Forested Riparian Buffers
Green Buildings for GHG Reduction
Rain Gardens and Porous Pavement
Smart Growth
Smart Roofs
Solarize Initiative


2015 Climate Change Action Plan Update
This report issued biennially by the state of Pennsylvania, provides a synopsis of climate change impacts to state resources including forests, aquatic and agricultural resources, and details carbon emissions across sectors. Thirteen work plans for state program initiatives to reduce emissions are included which focus principally on energy use and, to a lesser degree, other methane emissions reductions.

Adapting to a Changing Climate, Risks and Opportunities for the Upper Delaware River Region
An assessment of climate change impacts on the upper Delaware River area, its forests, waters, and communities.

DCNR 2016 State Forest Resource Management Plan
Synopsis of the priorities and plans of the state Bureau of Forestry,  including consideration of climate change.

DCNR and Climate Change:  Planning for the Future
A synthesis of climate knowledge as it relates to Pennsylvania and a planning perspective from the agency that oversees our state forests and parks.

Identifying Species in Pennsylvania Potentially Vulnerable to Climate Change
An analysis by the Pennsylvania Natural Heritage Program of 85 Pennsylvania species.

Local Phenology Data
The Eastern PA Phenology Project encourages the public to observe and record seasonal information on an array of plants and animals to build up a dataset on how annual life cycle events are trending over time.

Pennsylvania Birds Climate Vulnerability
National Audubon Society projections for North American birds developed from over fifty years’ of field observations.

Pennsylvania’s Challenge, Preserving the Kittatinny Ridge
A brochure for property owners interested in talking to one of the land trusts in the region about protection of their land.

Pennsylvania Climate Impacts Assessment Update
The latest in a series of reports summarizing impacts to Pennsylvania forests, water, wetlands, recreational and other resources.

Pennsylvania Wildlife Action Plan
2015 update prepared by the Pennsylvania Fish and Boat Commission and the Pennsylvania Game Commission; contains a chapter on climate change.

Weathering Climate Change:  Framing Strategies to Minimize Impacts on Pennsylvania Ecosystems and Wildlife
A 2010 snapshot of views from Pennsylvania agencies and organizations on the importance of developing strategies for addressing climate change and perspectives of what strategic actions are needed.


Audubon Climate Change Projections
A study looking at hundreds of species of birds and using historic data on how species ranges have been shifting to project what impact climate change will have over the next 50 years. The site provides state-specific findings on birds expected to be most affected by climate change.

Climate Adaptation Knowledge Exchange
Find information resources on climate adaptation here.

Climate Explorer
Explore maps and graphs of climate data in your area.  Both historical data and projections.

Forest Adaptation Resources:  Climate Change Tools and Approaches for Land Managers
Presents an approach to climate change adaptation for forested lands manager, with a suite of options appropriate to managing for climate change effects.

National Fish, Wildlife, and Plants Climate Adaptation Plan
Sets out goals and strategies for addressing climate change impacts on our nation’s flora and fauna.

Nature’s Notebook
Observations from fellow citizens on the seasons’ changes from year to year.  You can submit data to this national repository too.

The Northeast Climate Science Center develops and shares scientific information on climate change trends, impacts, and resource management effects.  The topics addressed by NECSC include: the current and future capacity of landscapes to support ecological functions and sustainable populations of plant and animal species;  species’ ecological vulnerability and response to climate change drivers (temperature, precipitation, etc.); and using new science to inform resource management decisions in the face of climate change uncertainties.

TNC Northeast Resilience Analysis
An assessment of landscape attributes such as topography and microhabitat distribution that foster climate resilience overlaid with an examination of biodiversity; the analysis identifies areas which may serve as lasting strongholds for biodiversity in the face of climate change.

Topography and Climate Adaptation in the Appalachians (and on the Kittatinny Ridge)
A discussion of expected effects of climate change on species range shifts and the importance of protecting both biodiversity area and corridors between them. Local upslope migrations and continental scale northward migrations are both touched upon. Concerns about plant species ability to move across shrinking upslope climate oases are mentioned.

USFS Changing Climate, Changing Forests:  Impact of Climate Change on Forests of the Northeastern United States and Canada
This analysis covers seven states and five Canadian provinces, looking at future forest conditions through the end of the century. While the region stops at the NY-Pennsylvania border for some of the information discussed, there is much useful information in this report. Analyses of projected changes to forest composition (i.e., changes in species mix) do include Pennsylvania.

Using Smart Growth to Adapt to Climate Change
Smart growth and and green building strategies can make neighborhoods and cities more resilient to climate change impacts, including flooding, sea-level rise, extreme heat, drought, and wildfire.


Energy Resources

An extremely important approach for helping fish, wildlife, and plants adapt to climate change is conserving enough suitable habitat to sustain diverse and healthy populations.

The National Fish, Wildlife, and Plants Climate Change Adaptation Strategy