Climate Change Is Happening – How Will It Affect Your Fly Fishing?

It’s a grim reality, but the fact remains that climate change is happening, and it stands to impact nearly every walk of life. Climate change will undoubtedly affect fly fishing and the river systems we know and love. Unfortunately, climate change–and how to address it–remains a highly politicized and controversial topic. Yet, there is overwhelming consensus among climate scientists that Earth’s climate is rapidly changing due to human activities.

According to a recent Pew Research Center poll, “about two-thirds (65%) of Americans say the federal government is doing too little to reduce the effects of climate change” and “a majority of Americans (63%) say that climate change is affecting their local community a great deal or some.”

Every day, we see and feel the effects of climate change. Extreme weather events are increasing and intensifying, and average sea levels are rising. These are just a couple examples of climate change’s effects. Climate change will also have a profound effect on water and food systems, property valuations, human health, ecosystems, and infrastructure. Despite the overwhelming nature of climate change’s associated risks, the U.S. Government is not doing enough, at this time.

In a recent polling of its members, Trout Unlimited found that “nearly nine in 10 Trout Unlimited members acknowledge that climate change is happening, and three in four are worried about global warming.”

To learn more about how climate change is impacting fly fishing, we talked to Dr. Max Holmes, Deputy Director of the Woods Hole Research Center. In addition to his work at the Woods Hole Research Center, Dr. Holmes recently started Science on the Fly, to study and protect rivers all around the world.


Flylords: Dr. Holmes, can you tell us a little bit about yourself and the Woods Hole Research Center?

Dr. Holmes: I’m a scientist and I’m a flyfisher, and in fact those things are very much linked.  I grew up in northern Michigan and spent most of my free time fishing.  When I wasn’t fishing I was still mucking around in streams, looking under rocks, and generally just having a good time on the water.  Somewhere along the line I learned that there were actually scientists who studied rivers, and that seemed like an awesome job to me.  That’s pretty much what I ended up doing.

I work at the Woods Hole Research Center, where I’m Deputy Director and Senior Scientist.  Scientists at the Woods Hole Research Center work around the world, studying how climate change is impacting nature, how changes in ecosystems can feedback to impact climate, and what we can do about it.  My own research focuses on rivers around the world, including in the Arctic (in Russia, Canada, and Alaska), the tropics (the Amazon and the Congo), and increasingly throughout the US as part of a new project we’re calling Science on the Fly.  In all of these studies we investigate river chemistry and discharge, how they are changing, and what that tells us about changes occurring in their watersheds.

Flylords: This may a good opportunity to spread some very general, science-based climate change information. Care to provide a brief overview of climate change?

Dr. Holmes: It’s hard to be brief on this topic but I’ll try.

Earth’s climate changes, and it did long before humans were in the picture starting a couple of hundred thousand years ago.

For the past 10,000 years, Earth’s climate has been remarkably stable.  During that time the human population has expanded from about 2 MILLION people to over 7.3 BILLION people.  Human civilization was able to develop, and human population was able to dramatically grow, precisely because of the unusually stable climate we’ve experienced for the past 10,000 years.

Around 1850, humans started using coal.  Around 1900, we started using oil.  And around 1950, we started using natural gas.  The combustion of these three fossil fuels, combined with deforestation, put vast amounts of heat trapping gases into the atmosphere, most importantly carbon dioxide.  As a result, the carbon dioxide concentration in the atmosphere has gone from 280 ppm to over 410 ppm now.

That causes the Earth to warm. It also causes changes to lots of other parts of the climate system, including amounts and timing of rainfall and snow, storm frequency and intensity, fires – almost all parts of the climate system.

Without aggressive action, things will get worse. Action now will make a huge difference for the future.  Fly fishers can and should have a powerful voice in pushing for action.

Dr. Holmes taking core samples in the Arctic

Flylords: To my understanding, there are many, many ways climate change can impact our rivers and fisheries. Can you highlight some of the more glaring impacts?

Dr. Holmes: As you said, there are many ways that climate change can impact rivers and their fish. Most obviously, water temperatures are increasing as the Earth warms, and that can have huge impacts on fish populations. The impacts can be direct–for example, different fish species have different temperature tolerances. The impacts can also be indirect–for example, warmer water contains less oxygen. In the case of trout, both of these factors can be crushing. Not only does warmer water speed up their metabolism, but they can’t get as much oxygen from the water to meet those metabolic requirements–-bad news all around. Climate change is also causing precipitation patterns to change, which can have a variety of impacts ranging from drying of streams to increasing flooding. And in the Arctic where I spend a lot of my time, permafrost (“permanently” frozen ground) is thawing, with a wide range of impacts on rivers, none of them good.

Flylords: What are scientists, like yourself, most worried about—in terms of climate change and fisheries?

Dr. Holmes: We’re already seeing big impacts from climate change, but future impacts threaten to be much greater if we don’t move much more aggressively to slow climate change.  So I worry about what the future will look like, whether there will be wild, native cutthroat in the Rockies, whether the Alaskan rivers I know and love will still team with salmon as they do now, and whether sea run brook trout will still be found on Cape Cod.  I also worry about how future generations will look back on us – we are aware of what we’re doing to the climate and environment, but so far we haven’t changed our behaviors in ways that would stabilize the climate for the benefit of future generations.

Flylords: Because of climate change’s global scale and potentially unavoidable impacts, I think it’s easy for anglers to feel amazingly under-gunned and helpless. Are there ways everyday fly fishermen and women can address climate change, or at least lessen their impacts?

Dr. Holmes: This is a super important question so I’m really glad you asked it. In the face of an enormous challenge like climate change, we can either give up and enjoy the party while it lasts, or get to work and fight like hell for what we love. Fly fishers are a passionate bunch who care deeply about the amazing places where we fish, so we should be in the fight like hell crowd.

So what to do?

Vote, and vote at all levels: local, state, and federal. Regardless of your political affiliation, let your candidates know they you care about the environment and climate change, and you expect them to take action.

Take someone fishing. Too many people are disconnected from nature, and without a deep connection with nature, people are less likely to fight to protect it. Fly fishing is just such an awesome way to fall in love with the amazing world we live in.

Think about your own individual actions, particularly related to energy use. Use less energy, and try to use renewable energy sources.

Plant a tree. Nothing is better at pulling carbon out of the atmosphere!

Volunteer with conservation organizations. There is a lot of work to be done, and there are a lot of good organizations out there. They could use your financial support too!

Check out Science on the Fly.  We’re working to bring the fly fishing and science communities together – for rivers and for climate.

Most importantly, do something!  As Edward Abbey said, “Sentiment without action is the ruin of the soul.”


Pebble Mine Final Environmental Impact Statement: Faulted, Rushed, Still Bad for Salmon

Meet the Prehistoric Saber-Toothed Salmon

Meet the Prehistoric Saber-Toothed Salmon


  1. Global warming is happening . Global warming has been happening for 12000 years since the mile high glaciers started melting. This warming is called the Holocene Interglacial. The actual climate has not changed as that is a 34 million year old Ice Age. The last interglacial, called the Eemian occurred about 115,000 years ago and was warmer by 2C at this stage. After the Eemian ended, glaciers returned for 125,000 years until the Holocene began. The Earth will get 3-5 C hotter over the next 2000-5000 years and then get colder and glaciers will return.
    This is not new science and can be confirmed easily by any search of the Holocene.
    CO2 is actually barely high enough for plants to grow. Earth is a cold planet barely warm enough to support life on much of the planet.
    So, the scientist is right that people need to be more in touch with nature as it is hard to understand how disconnected people have to be to worry about heat during an Ice Age. Or, to worry about CO2 when the plants are stunted due to low CO2.
    That is the real science and easily looked up.So, how can this ‘scientist ‘ mention none of this ?
    Sadly, we live in an age of politicized science not seen since the Aztec kings told the Aztec citizens that sacrifices were needed to bring the weather for farming.
    Yes, it is getting hotter…for 12000 years .

  2. I appreciate the comment by siempre44. He or she clearly is passionate about climate and the environment, which I think is a great thing. And there is actually a lot we agree on including that the earth warning and that the earth’s climate has always changed. Where we seem to disagree is whether human activities are currently having a significant impact on Earth’s climate: I’m absolutely convinced that the answer is yes, but siempre44 seems equally convinced that the answer is no.

    In cases like this, I like to start by figuring out what we agree on, and then figure out where our understanding or conclusions diverge. So, siempre44, would you agree that:

    1. CO2 is a heat trapping gas?
    2. Atmospheric CO2 concentration was around 280 ppm (+/- 10 ppm or so) for the past 10,000 years, until about 1850?
    3. Since 1850, CO2 concentration in the atmosphere has been increasing, and it is currently over 400 ppm?

    My guess is that we are on the same page until now, each of us answering Yes to those first three questions.

    If so, would you then agree that:

    4. We know why CO2 has increased in the atmosphere since 1850, mainly the burning of fossil fuels (coal, oil, and natural gas), and also deforestation?

    I suppose that we are still on the same page, each answering Yes to question 4 as well.

    Before continuing though, I’ll wait to hear that in fact we do agree on those first 4 points.

    Thanks again for your interest,

    Max Holmes

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