David Wallace-Wells' "The Uninhabitable Earth" paints a chilling picture of our planet's future if we continue on our current trajectory of climate change. This eye-opening book lays out the devastating consequences of global warming and how they will reshape life on Earth as we know it. Wallace-Wells argues that the situation is far more dire than most people realize, and that we are rapidly approaching tipping points that could lead to catastrophic and irreversible changes to our world.
The book explores how climate change will impact everything from food production and freshwater availability to human health, economic systems, and geopolitics. It examines both the direct effects of rising temperatures as well as the cascading and compounding disasters that could be triggered. While the outlook presented is undeniably bleak, Wallace-Wells' intent is not to instill hopelessness but rather to shake us out of complacency and spur urgent action.
"The Uninhabitable Earth" serves as a stark wake-up call about the existential threat posed by climate change. It challenges us to confront the full scale and scope of the crisis we face. By laying out the science in vivid and accessible terms, Wallace-Wells makes it impossible to ignore the perilous future that awaits us if we fail to dramatically change course. This summary will explore the key ideas and warnings presented in this important book.
The Paris Agreement's Goals Are Hopelessly Optimistic
In 2015, world leaders gathered in Paris to negotiate a new global climate agreement. The resulting Paris Agreement set an ambitious goal of limiting global temperature rise to well below 2°C above pre-industrial levels, with efforts to limit the increase to 1.5°C. This was widely hailed as a major breakthrough in global climate action.
However, Wallace-Wells argues that the goals set in Paris are hopelessly optimistic and virtually impossible to achieve at this point. Even if all countries fully implemented their pledges under the agreement - which most are not on track to do - we would still blow past the 2°C threshold.
According to projections from the UN Intergovernmental Panel on Climate Change (IPCC), even with aggressive action starting immediately, we are likely headed for at least 3.2°C of warming by 2100. This assumes countries enact all the policy changes agreed to in Paris, which is far from certain. No major industrialized nation is currently on pace to meet its Paris commitments.
The implications of 3°C+ warming are severe:
- Collapse of polar ice sheets, eventually flooding over 100 major coastal cities
- Permanent drought conditions across southern Europe
- 600% increase in annual wildfire damage in the US
- Large parts of the tropics becoming essentially uninhabitable
And this is the optimistic scenario. The UN's worst-case projections show up to 8°C of warming by 2100, which would render vast swaths of the planet unlivable.
Wallace-Wells emphasizes how rapidly climate change is accelerating. Over half of all carbon emissions in human history have occurred in just the last 30 years. The damage has been done in the span of a single generation. This means the burden of addressing it falls squarely on our shoulders now.
The author's intent is not to instill hopelessness, but to strip away comforting illusions and force us to confront the true gravity of the situation. Only by understanding how far past sustainable limits we've already pushed can we grasp the urgency and scale of action required.
Climate Change Effects Create Destructive Feedback Loops
One of the most worrying aspects of climate change is how its various effects can compound and accelerate one another through feedback loops. Wallace-Wells explores several of these "climate cascades" that threaten to push warming beyond our control.
A prime example is the melting of Arctic sea ice. As highly reflective ice melts, it exposes darker water that absorbs more heat. This leads to more warming and more ice melt in a vicious cycle. The loss of sea ice is already outpacing even worst-case projections from climate models.
Another major concern is melting permafrost in Arctic regions. As frozen soil thaws, it releases massive amounts of trapped carbon and methane - potent greenhouse gases that cause more warming. Scientists estimate permafrost contains up to 1.8 trillion tons of carbon, twice what's currently in the atmosphere.
Wildfires represent another destructive feedback loop:
- Higher temperatures and drought create more fire-prone conditions
- More severe fires burn through more forest
- Burned forests release stored carbon and reduce carbon absorption
- More carbon in the atmosphere leads to more warming
- Cycle repeats with even worse fires
The Amazon rainforest, often called the "lungs of the planet" for its massive carbon absorption, is particularly vulnerable to this cycle. Parts of the Amazon may already be close to a tipping point where forest dieback becomes self-reinforcing.
Ocean acidification is another compounding effect. As oceans absorb more CO2, they become more acidic. This kills off coral reefs and plankton that play a crucial role in marine food chains and carbon sequestration. Their loss further reduces the ocean's capacity to absorb carbon.
These are just a few examples of how climate impacts can spiral into self-amplifying disasters. The interconnected nature of Earth's systems means seemingly small changes can trigger cascading effects throughout the entire climate. This makes the crisis even harder to model or predict with certainty.
The existence of these feedback loops and tipping points means there's a real risk of runaway warming that spins beyond human control. It's one of the most frightening aspects of climate change and a key reason for urgency in emissions reduction. We may be closer to irreversible tipping points than we realize.
Extreme Weather Becomes the New Normal
One of the most immediately noticeable effects of climate change is the increase in extreme weather events. Wallace-Wells paints a picture of a future where what we now consider severe or anomalous weather becomes commonplace.
As air warms, it can hold more moisture. This leads to more intense rainfall and flooding during storms. At the same time, warmer temperatures increase evaporation, exacerbating droughts in dry areas. The result is more frequent swings between flooding and drought conditions.
Hurricanes and tropical storms are becoming more powerful as they feed off warmer ocean waters. The number of Category 4 and 5 hurricanes has already increased 25-30% for each degree of warming so far. By 2100, mega-storms as strong as Hurricane Katrina could occur twice as often.
Some key statistics highlight how rapidly extreme weather is escalating:
- The number of floods and other hydrological events has quadrupled since 1980
- Climatological events like extreme temperatures, droughts, and forest fires have more than doubled since 1980
- Storm damage in the U.S. has increased seven-fold since 1980
- Power outages from storms have doubled since 2003
In 2017, we saw an ominous glimpse of this future when two Category 5 hurricanes (Irma and Maria) struck the Caribbean in quick succession. The compounded damage from these storms created a major humanitarian crisis, particularly in Puerto Rico where many were left without power or running water for months.
Wallace-Wells emphasizes that this level of weather chaos will become increasingly normal. What were once considered freak events may soon feel routine. This has profound implications for infrastructure, agriculture, and daily life in many parts of the world.
The economic toll of more frequent disasters will be enormous. Already, climate-related weather disasters cause over $300 billion in damage annually. As extreme events become more common, the cost of rebuilding and adaptation will strain government budgets and the insurance industry.
Perhaps most alarmingly, our infrastructure and systems are not built to withstand this new normal. Power grids, transportation networks, and cities designed for 20th century climate patterns will face mounting stress. Upgrading this infrastructure will require massive investment at a time when disaster recovery costs are also rising.
The shift to more extreme and unpredictable weather will force changes to agriculture, urban planning, building codes, and many other aspects of society. Adapting to this new reality poses an immense challenge even as we struggle to mitigate further warming.
Rising Seas Will Redraw the Map of the World
Sea level rise is one of the most certain and visible consequences of climate change. As polar ice melts and warming oceans expand, coastal regions around the world face existential threat. Wallace-Wells examines how rising seas will reshape coastlines and force the relocation of millions.
Current projections show sea levels rising between 1.2 and 2.4 meters (4-8 feet) by 2100 if emissions continue unabated. This may sound modest, but the implications are staggering:
- Bangladesh, home to 164 million people, would be largely underwater
- Many of the world's most iconic beaches would disappear
- Coastal cities like Miami, Shanghai, and Hong Kong face severe flooding
- Landmarks like the White House and St. Mark's Basilica in Venice would be inundated
Some effects will arrive much sooner. Jakarta, Indonesia's capital of 10 million people, is already sinking and could be mostly underwater by 2050. Island nations like the Maldives may become uninhabitable within decades.
Longer-term projections are even more dramatic. Failing to reduce emissions could lead to 6 meters (20 feet) of sea level rise over the coming centuries. This would redraw coastlines around the world, swallowing 444,000 square miles of land containing ports, power plants, naval bases, farmlands, and many major cities.
The economic toll will be enormous. Trillions of dollars of coastal real estate and infrastructure are at risk. Entire industries and supply chains will be disrupted as ports flood. And the cost of protecting or relocating coastal populations will strain national budgets.
Sea level rise also threatens critical digital infrastructure. Many of the fiber optic cables and data centers that power the internet are in coastal areas vulnerable to flooding. Climate change could quite literally break the internet in some regions.
Wallace-Wells emphasizes how sea level rise will exacerbate inequality both within and between nations. Wealthy individuals and countries can afford to adapt or relocate, while the poor are left exposed. Developing nations with large coastal populations face particularly severe threats to their economic and political stability.
The author also highlights how slowly we're responding to this threat. Despite clear warnings, coastal development continues in many at-risk areas. The scale of the coming changes still hasn't sunk in for many policymakers and members of the public.
Ultimately, Wallace-Wells argues that sea level rise will force a mass migration inland unprecedented in human history. Hundreds of millions may be displaced in the coming decades. Managing this upheaval humanely and peacefully poses an immense political and logistical challenge.
Climate Change Threatens Global Food Security
Food production is highly vulnerable to climate change, posing a severe threat to global food security in the coming decades. Wallace-Wells examines how rising temperatures, extreme weather, and other climate impacts will strain agricultural systems and potentially trigger widespread food shortages.
Grain crops like wheat, rice, and corn form the foundation of the global food supply, accounting for about two-thirds of all calories consumed by humans. But these staple crops are highly sensitive to temperature changes. For every degree Celsius of warming, grain yields decline by about 10%.
This creates an alarming math problem. By 2050, we'll need to nearly double food production to feed a growing population. But if we hit 4-5°C of warming by then, we could see a 40-50% decline in yields. The gap between food needs and production capacity could become catastrophic.
Several factors compound this challenge:
Prime agricultural regions are becoming less suitable for farming as temperatures rise. The global "wheat belt" is shifting about 160 miles north each decade.
Extreme weather like floods, droughts, and heat waves is becoming more frequent, leading to more crop failures.
Warming is reducing the nutritional value of crops. Studies show that plants grown in CO2-rich environments have up to 33% less protein and minerals.
Water scarcity will limit irrigation as glaciers that feed major rivers melt and rainfall patterns shift.
Rising seas will inundate fertile coastal lands and river deltas.
Ocean acidification and warming threatens fisheries that many rely on for protein.
Wallace-Wells notes that food insecurity is already a major issue, with over 800 million people undernourished globally. Climate change threatens to dramatically worsen this situation and potentially trigger famines affecting hundreds of millions.
Food shortages can also spark political instability and conflict. Some researchers argue that climate-induced crop failures played a role in triggering the Arab Spring uprisings. As resources become scarcer, the risk of food-related unrest will grow.
Adapting agriculture to a warming world is possible but challenging. It will require developing heat and drought-resistant crop varieties, shifting growing regions, improving irrigation efficiency, and reducing food waste. But the pace of change may outstrip our ability to adapt, especially in poorer regions.
The author argues that avoiding a global food crisis will require both aggressive emissions reductions and major investments in agricultural resilience and innovation. Failure to act could lead to widespread hunger and malnutrition on a scale not seen in modern times.
Warming Temperatures Will Spread Disease
Climate change poses a major threat to human health, in part by altering the spread and intensity of infectious diseases. Wallace-Wells explores how a warming planet creates more hospitable conditions for many pathogens and disease vectors.
One alarming possibility is the revival of ancient diseases trapped in melting permafrost. Arctic ice contains bacteria and viruses that have been frozen for millennia, including some humans have never encountered. As this ice thaws, it could release long-dormant pathogens our immune systems are not prepared for.
This isn't just a theoretical concern. In 2016, an anthrax outbreak in Siberia was linked to a decades-old reindeer carcass exposed by melting permafrost. Researchers have also found still-viable Spanish flu virus in Alaskan ice. The release of truly ancient microbes is an even more uncertain threat.
However, the more immediate concern is how climate change will affect current diseases:
Warmer temperatures allow disease-carrying insects like mosquitoes and ticks to expand their ranges. This is already happening with diseases like malaria, Zika, and Lyme disease appearing in new regions.
Longer warm seasons extend the active period for many disease vectors.
Increased rainfall and flooding in some areas create more standing water for mosquitoes to breed.
Warming oceans allow water-borne pathogens like cholera to thrive and spread more easily.
Heat waves and air pollution weaken people's immune systems, making them more susceptible to disease.
Wallace-Wells cites several examples of how this is already playing out:
- Malaria-carrying mosquitoes are being found at higher altitudes in Africa as temperatures rise.
- Lyme disease has spread rapidly across the US as warming expands tick habitats.
- Dengue fever is projected to put an additional 2 billion people at risk by 2080 due to climate change.
The health impacts extend beyond infectious disease. Heat itself is a major killer, with heat waves causing thousands of deaths even in developed countries. Air pollution, exacerbated by warming, causes millions of premature deaths annually.
Mental health is another often overlooked casualty. Studies have linked air pollution to increased rates of depression, anxiety, and even dementia. The stress and trauma of climate-related disasters also take a major psychological toll.
Perhaps most alarmingly, some research suggests that rising CO2 levels could directly impair human cognition. At projected 2100 CO2 concentrations, cognitive ability could decline by 21% - a staggering hit to human productivity and quality of life.
Wallace-Wells argues that our health systems are ill-prepared for these compounding threats. Many hospitals and clinics, especially in developing regions, already struggle to meet current needs. Climate change will strain these systems even further while potentially compromising medical supply chains.
Ultimately, the author paints a picture of a sicker world, where both old and new diseases threaten human health and wellbeing on an unprecedented scale. Avoiding this future will require both emissions reduction and major investments in global health resilience.
Air Pollution Creates a Global Health Crisis
Air pollution emerges as one of the most immediate and severe health threats posed by climate change. Wallace-Wells examines how a warmer planet is exacerbating air quality issues, with dire consequences for human health and cognitive function.
The scale of the current air pollution crisis is staggering:
- 98% of cities in low and middle-income countries exceed WHO air quality guidelines
- In 2017, breathing New Delhi's air was equivalent to smoking 44 cigarettes a day
- Globally, air pollution causes about 1 in 6 deaths - over 10,000 people daily
Air pollution doesn't discriminate - it affects young and old, rich and poor alike. But some of the most vulnerable groups, like children and pregnant women, suffer disproportionately. Studies have linked air pollution to increased rates of mental illness in children and dementia in the elderly.
Climate change worsens air quality through several mechanisms:
- Higher temperatures increase the chemical reactions that produce smog and ozone.
- More frequent wildfires pump smoke and particulates into the air.
- Drought conditions lead to more dust storms.
- Warming-induced changes in air circulation patterns can trap pollutants over cities.
Beyond the direct health effects, Wallace-Wells highlights how air pollution impairs cognitive function. When carbon dioxide concentrates in enclosed spaces, it can significantly reduce mental performance. One study found that at CO2 levels we may reach globally by 2100, cognitive ability could decline by 21%.
This effect is already measurable. A 2018 study in China found that reducing air pollution to US EPA standards would boost verbal test scores by 13% and math scores by 8%.
The economic toll of air pollution is enormous. Beyond healthcare costs, reduced cognitive function and lost productivity cost the global economy trillions annually. And as air quality worsens, these impacts will only grow.
Cleaning up our air would yield immense and immediate benefits. Unlike many climate impacts that play out over decades, air quality improvements can be felt within weeks. This makes it a compelling target for near-term action.
However, many of the world's most polluted cities are in rapidly developing countries that rely heavily on fossil fuels. Balancing economic growth with air quality is a major challenge. And as the planet warms, maintaining air quality will become increasingly difficult even with emissions reductions.
Wallace-Wells argues that the air pollution crisis epitomizes the intersecting health, economic, and social justice dimensions of climate change. Addressing it will require reimagining our energy systems, urban design, and economic priorities. But the potential gains in health and quality of life make it one of the most urgent priorities in combating climate change.
Freshwater Scarcity Becomes a Global Crisis
Access to clean freshwater is essential for human life, agriculture, and many industries. But climate change threatens to create widespread water scarcity, potentially affecting billions of people. Wallace-Wells examines how warming temperatures, shifting precipitation patterns, and other climate impacts are straining freshwater resources around the world.
While water covers most of the Earth's surface, only about 2% is freshwater. And just 1% of that freshwater is easily accessible in rivers, lakes, and aquifers. Historically, this has been enough to meet human needs. But climate change is upsetting this delicate balance.
Several factors are converging to create a global water crisis:
Rising demand: By 2030, global freshwater demand is projected to exceed supply by 40%, driven by population growth, urbanization, and increased agricultural and industrial use.
Shrinking supplies: Many of the world's largest lakes and rivers are drying up due to overuse and changing climate patterns. For instance, Lake Chad in Africa has lost 95% of its volume since the 1960s.
Disrupted water cycles: Climate change is altering precipitation patterns, leading to more intense droughts in some regions and floods in others. This makes water supplies less reliable and harder to manage.
Melting glaciers: About half the world relies on seasonal meltwater from mountain snow and glaciers. As these ice reserves shrink, it threatens water security for billions.
Saltwater intrusion: Rising seas are contaminating coastal aquifers, reducing freshwater availability in many regions.
The UN estimates that by 2050, 5 billion people could face water shortages. The hardest hit areas will likely be in Africa, the Middle East, and parts of Asia. But even developed countries aren't immune - the American Southwest, for instance, faces severe long-term water challenges.
Water scarcity has profound ripple effects. It threatens food production, energy generation, public health, and economic development. It can also drive political instability and conflict. Some researchers argue that water stress played a role in sparking the Syrian civil war.
Wallace-Wells emphasizes how water issues intersect with other climate impacts. Drought makes wildfires more likely. Water shortages can cripple power plants and other critical infrastructure. And lack of clean water makes populations more vulnerable to heat waves and disease outbreaks.
Adapting to water scarcity will require major investments in infrastructure and technology. Improving irrigation efficiency, developing drought-resistant crops, and expanding water recycling and desalination capacity will all be crucial. But these adaptations are expensive and energy-intensive, creating additional challenges.
The author argues that avoiding a global water crisis will require both dramatic emissions reductions and a fundamental rethinking of how we use and value water. Price signals, conservation measures, and more equitable water-sharing agreements will all be necessary. But time is running short to implement these changes before shortages become acute in many regions.
Climate Change Drives Conflict and Migration
As climate change reshapes the physical world, it will also transform human societies and geopolitics. Wallace-Wells explores how global warming is likely to fuel conflict and drive mass migration in the coming decades.
The links between climate and conflict are complex, but several pathways are clear:
Resource scarcity: As climate change threatens food and water supplies, competition for these resources is likely to intensify both within and between nations.
Economic disruption: Climate impacts like floods, droughts, and sea level rise can devastate local economies, breeding instability and unrest.
Forced migration: As some regions become less habitable, climate refugees will strain social and political systems in their new homes.
Extreme weather: More frequent disasters can overwhelm governments and fray social cohesion.
Research suggests that for each half-degree of warming, the chance of armed conflict anywhere in the world increases by 10-20%. Some regions are particularly vulnerable. In Africa, studies indicate climate change has already increased conflict risk by over 10%.
Even on a personal level, heat has been linked to increased aggression and violence. Everything from road rage to violent crime tends to spike during heat waves. One study projected climate change could lead to an additional 22,000 murders in the US by 2100.
Mass migration may be one of the most disruptive consequences of climate change. The World Bank estimates that by 2050, there could be 143 million climate migrants from just three regions (Latin America, sub-Saharan Africa, and Southeast Asia). Other estimates run as high as 1 billion climate refugees globally by mid-century.
This scale of human movement is unprecedented in modern history. It threatens to overwhelm social services, alter cultural dynamics, and fuel political backlash in receiving areas. Even in wealthy nations, absorbing millions of climate refugees will pose immense challenges.
Wallace-Wells notes that climate-driven migration is already happening. It played a role in Syria's civil war and the European migrant crisis. In the US, thousands have been displaced by worsening wildfires and hurricanes. But the coming decades could see migration on a much larger scale.
The author emphasizes that climate change acts as a threat multiplier, exacerbating existing tensions and inequalities. Poor and marginalized communities will likely bear the brunt of climate impacts and have fewer resources to adapt. This could widen social divides and fuel grievances.
Ultimately, Wallace-Wells argues that climate change will reshape the geopolitical map in profound and unpredictable ways. Alliances may shift as nations compete for dwindling resources. Some countries may collapse under environmental pressures. And the scale of human movement could redraw cultural and demographic lines across continents.
Mitigating these disruptions will require unprecedented international cooperation. But climate impacts may also make such cooperation more difficult, creating a vicious cycle. How humanity navigates these challenges may define the course of the 21st century.
Technological Solutions Exist But Face Major Hurdles
In the face of such dire projections, many pin their hopes on technological solutions to climate change. Wallace-Wells examines some of the most promising approaches, but cautions that they face significant obstacles to deployment at the necessary scale.
Two main categories of tech solutions have gained traction:
Negative emissions technologies that actively remove carbon from the atmosphere.
Solar geoengineering approaches that reflect sunlight to cool the planet.
On the negative emissions front, the most discussed option is bioenergy with carbon capture and storage (BECCS). This involves growing crops that absorb CO2, burning them for energy, then capturing and storing the emissions underground. In theory, this could produce energy while reducing atmospheric carbon.
Another approach uses machines to directly capture CO2 from the air. These "artificial trees" already exist and work similarly to plant photosynthesis.
The main challenge for these technologies is scale. To make a meaningful dent in atmospheric CO2, we'd need to deploy them at an enormous scale. One study suggested BECCS would require land equal to one-third of current global cropland - unrealistic given food production needs. For direct air capture, we'd need about 100 million machines, costing an estimated $30 trillion.
Solar geoengineering faces different hurdles. The most discussed method involves injecting reflective particles into the upper atmosphere to mimic the cooling effect of a volcanic eruption. While potentially effective at lowering temperatures, it carries major risks. It could disrupt weather patterns, damage the ozone layer, and create diplomatic tensions over who controls the global thermostat.
Perhaps the biggest issue with geoengineering is that it doesn't address ocean acidification or other non-temperature effects of CO2. It's also addictive - once started, it would have to be maintained indefinitely or temperatures would rapidly rebound.
Wallace-Wells emphasizes that while these technologies shouldn't be dismissed, they're not silver bullets. Many have unintended consequences we don't fully understand. And relying on speculative future tech could reduce the urgency of emissions cuts now.
The author argues that the most viable near-term tech solutions involve scaling up existing clean energy sources like solar and wind, improving energy efficiency, and electrifying transport and industry. While less flashy than sci-fi-esque carbon capture machines, these proven technologies can make a major dent in emissions if deployed aggressively.
Ultimately, Wallace-Wells contends that there's no purely technological fix to climate change. While innovation will play a crucial role, it must be paired with dramatic policy changes and shifts in human behavior. Waiting for a miracle technology to save us is a dangerous gamble given the urgency of the crisis.
Conclusion: We Must Act Now to Shape Our Climate Future
In the final section, Wallace-Wells reflects on the enormity of the challenge we face and the urgent need for action. While the outlook he presents is undeniably bleak, he argues that we still have the power to shape our climate future - if we act swiftly and decisively.
The author emphasizes several key points:
The worst outcomes are not inevitable. Every fraction of a degree of warming we prevent matters enormously. The difference between 2°C and 3°C of warming, or between 3°C and 4°C, is the difference between difficult adaptation and potential civilizational collapse.
We have the tools we need. Renewable energy, energy efficiency, sustainable agriculture, and other existing technologies can dramatically cut emissions if deployed at scale. The obstacles are primarily political and economic, not technological.
Time is of the essence. The next decade is crucial. The longer we delay serious action, the more drastic future cuts will need to be to avoid catastrophic warming.
Climate action has immense co-benefits. Many climate solutions also improve public health, create jobs, enhance energy security, and address inequality. These near-term benefits can help build political will for action.
We need both mitigation and adaptation. Even if we cut emissions dramatically, some degree of warming is locked in. We must prepare for the impacts while working to minimize them.
Wallace-Wells argues that confronting climate change will require reimagining our economic and political systems. The scale of the challenge demands a World War II-level mobilization of resources and a fundamental shift in how we relate to the natural world.
He acknowledges the immense difficulty of this task but contends that the alternative - allowing warming to continue unchecked - is simply unacceptable. The suffering it would inflict, particularly on the world's most vulnerable, creates a moral imperative to act.
The author closes with a call for engagement and action at all levels - individual, community, national, and global. While personal lifestyle changes are important, he emphasizes the need for systemic change through policy and collective action. Getting involved politically, supporting climate-focused organizations, and shifting investments away from fossil fuels are all crucial steps.
Ultimately, Wallace-Wells leaves us with a stark choice. We can resign ourselves to a deteriorating climate and the immense human toll it will take. Or we can rise to what may be humanity's greatest challenge and work to create a sustainable future. The path we choose will define the course of life on Earth for centuries to come.
"The Uninhabitable Earth" is a sobering but essential read that strips away comforting illusions about climate change. By unflinchingly examining the potential consequences of inaction, it aims to galvanize the kind of urgent, large-scale response the crisis demands. While the future Wallace-Wells describes is frightening, the book's underlying message is that this future is not yet written. Our actions in the coming years will determine whether we can create a livable planet for generations to come.