Humanity is now facing a significant environmental crisis, marked by issues like biodiversity loss, climate change and pollution. These problems have cascading effects, impacting ecosystems, economies and human health worldwide. However, there’s a lot we can still do to reverse the damage.
We’re facing a climate emergency right now where environmental degradations, rising temperatures and extreme weather events are jeopardizing life on Earth. The climate conditions we’re stepping into have never been encountered in human history. Scientists warn that we will soon reach irreversible tipping points, such as the breakdown of ice sheets, if we don’t drastically reduce our reliance on fossil fuels.
It’s easy to feel helpless and lose hope when living under such dire predictions, day after day. It can make you want to keep your head down, go on with business as usual and pretend it will all go away. But shrugging it off isn’t the best course of action or even necessary, because now a first-of-its-kind study finds that with some simple but bold and coordinated policy choices—involving diets, emissions, food waste, and nitrogen and water efficiency—humanity could, by 2050, bring global environmental pressures back to levels seen in 2015. This shift would move us much closer to a future in which people around the world can live well within the Earth’s limits.
For example, in the diet category, something as simple as switching drink and food purchases to very similar but more environmentally-friendly alternatives could reduce the greenhouse gas emissions from household groceries by more than a quarter. In the emissions field, engineers have recently created a more efficient way of converting carbon dioxide into valuable products while simultaneously addressing climate change.
Freshwater availability is one of the nine planetary boundaries that scientists say we have already crossed. Human activities, including irrigation, have impacted freshwater resources, leading to changes in the water cycle.
Pushing environmental pressures back
The planetary boundaries framework, first introduced by an international team of scientists in 2009, defines nine critical Earth system processes that maintain the conditions under which human societies have flourished for the past 10,000 years. Crossing these boundaries increases the risk of destabilizing how the Earth functions, pushing it into a much less hospitable state. To date, scientists estimate that six of the nine planetary boundaries have already been crossed: those related to biosphere integrity, climate change, freshwater change, land system change, modification of biogeochemical flows (the disruption of the natural nutrient cycles of key elements, such as nitrogen and phosphorus) and novel entities (the introduction of novel entities includes synthetic chemicals and substances, such as microplastics; anthropogenically mobilized radioactive materials, such as nuclear waste; and human interventions in evolutionary processes, such as genetically modified organisms or GMOs).
But a new study, led by scientists at Utrecht University in the Netherlands and which was published in the journal Nature in May 2025, for the first time shifts focus to the future, exploring whether ambitious but technically feasible policies could change our trajectory. It’s the first time a forward-looking global model has been used to ask: How do things develop if we continue like this? Can we still avoid transgressing or come back from transgressing these boundaries? And if so, what would it take?
To answer these questions, the planetary boundaries framework was coupled to a comprehensive integrated assessment model, which describes future human development and the possible impacts on the global environment. The model projected outcomes for eight of the nine planetary boundaries under different future scenarios, including those with strong environmental policy actions.
Another crossed planetary boundary is biosphere integrity. Biodiversity loss due to growing pressure on ecosystems to supply us with energy, food, land and water is causing a reduction in biosphere integrity—as evidenced by increasing species extinctions. Amur leopards are now critically endangered.
Critical systems like biodiversity and climate are already outside safe limits, with most exceeding even the high-risk thresholds, indicating a looming multicrisis scenario. Using projections for 2030, 2050 and 2100, the study shows that under current trends, all planetary boundaries except for ozone depletion are expected to be breached by 2050. And, say the researchers, if we continue down pathways focused on local or national interests, things could deteriorate even further, emphasizing the need for coordinated global action.
However, the researchers identified five measures that together could significantly reduce environmental transgressions:
1) Reduce food waste. We could cut global food waste in half by reducing losses in supply chains and in overconsumption.
Reducing food waste could substantially reduce our environmental transgressions. Composting is an effective method of reducing food waste. By transforming food scraps into a nutrient-rich soil amendment, we keep organic matter out of landfills, where it produces methane, a greenhouse gas.
2) Improve water-use efficiency. To ensure environmental sustainability, we should reduce water withdrawal for energy, households and industry by 20% and for irrigation by 30%.
3) Improve nitrogen-use efficiency. We need to increase the efficiency of using nutrients (such as nitrogen) between 70% and 80% in agriculture by 2050, up from 50% today.
4) Change food consumption. We must shift to diets that are both healthy and good for the environment, as defined by the EAT-Lancet Commission, reaching 80% global uptake by 2050. The EAT-Lancet report is the first full-scientific review of what constitutes a healthy diet from a sustainable food system and which actions can support and speed up food system transformation.
5) Mitigate climate change. Committing to achieving the Paris Agreement’s 1.5 degrees Celsius (about 2.7 degrees Fahrenheit) target through the aggressive reduction of greenhouse gas emissions is imperative.
“Nitrogen use efficiency” refers to the proportion of applied nitrogen that is used by plants for growth and yield rather than being lost to the environment. It essentially measures how effectively a crop draws the nitrogen provided through fertilizer or other sources.
Combined, these measures could return the pressure on our planet to roughly that of 2015—a marked improvement over current projections and a crucial step toward ensuring long-term human well-being while staying within the Earth’s limits.
The authors of the study caution, however, that the assumptions behind these scenarios are ambitious. Systems are slow to change, and this is a model of near-universal shifts—like widespread dietary changes—which may be overly optimistic given current global trends.
Making food swaps
There’s one easy way to make a change in your food consumption (No. 4, above) and help to mitigate climate change (No. 5, above) at the same time. According to a new science paper from The George Institute for Global Health in Australia and the Imperial College London, published in the journal Nature Food in May 2024, you could achieve both by switching your drink and food purchases to very similar but more environmentally-friendly alternatives. This study is the most detailed analysis ever conducted on the environmental impacts of a country’s food-purchasing behaviors, involving comprehensive data on greenhouse gas emissions and sales for tens of thousands of supermarket products typical of the Western diets of many nations.
The planetary health diet is symbolically represented by half a plate of fruits, nuts and vegetables. The other half consists primarily of whole grains, plant proteins, unsaturated plant oils, modest amounts of dairy and meat, and some starchy vegetables and added sugars.
Dietary habits need to radically change if we are to meet global emissions targets, particularly in high-income countries like Australia, the United Kingdom and United States, say the scientists. But while consumers are increasingly aware of the environmental impact of the food system and are willing to make more sustainable food choices, they lack reliable information to identify the more environmentally-friendly options. Indicating the greenhouse gas emissions on the label of every packaged food product would help consumers to make informed choices.
Researchers calculated the projected emissions of annual grocery purchases from 7,000 Australian households using information on ingredients, weights and production life cycles in The George Institute’s FoodSwitch database and global environmental impact datasets. More than 22,000 products were assigned to major, minor and subcategories of foods (for example, “bread and bakery,” “bread” and “white bread,” respectively) to quantify emissions saved by switching both within and between groups.
Results showed that making switches within the same subcategories of foods could lead to greenhouse gas emission reductions of 26% in Australia, equivalent to taking more than 1.9 million cars off the road. Switches within minor categories of foods—like swapping frozen meat lasagna for the vegetarian option—could push the reduction to as much as 71%. These switches would not compromise food healthiness overall; in fact, they would lead to a slight reduction in the proportion of ultra-processed foods purchased, a positive outcome because they’re generally less healthy.
We can significantly reduce our environmental impact by switching like-for-like products. A simple food swap like opting for vegetarian lasagna instead of the meat version can push reductions in greenhouse gas emissions.
The purchase analysis also showed that meat products were only 11% of total purchases but contributed almost half (49%) of all greenhouse gas emissions. Conversely, fruit, legumes, nuts and vegetables represented one quarter (25%) of all purchases, but were responsible for just 5% of emissions.
According to the researchers, as a global community, we are taking too long to improve the sustainability of the food system, endangering the prospect of a net-zero future. There is currently no standardized framework for regulating the climate or planetary health parameters of our food supply, and voluntary measures have not been widely adopted by most countries. Innovative ways of approaching the problem could enable consumers to make a real impact. With that in mind, the scientists developed a free app called ecoSwitch that’s based on this research and currently available in Australia. Shoppers can use their device to scan a product barcode and check its “Planetary Health Rating,” a measure of its emissions shown as a score between half a star (high emissions) to five stars (low emissions).
There are plans to extend the ecoSwitch algorithm to integrate other environmental indicators, such as biodiversity and land and water use, and to introduce the tool to other countries. While ecoSwitch is a much-needed first step in providing environmental transparency for grocery shoppers, the vision is for a mandatory display of a single, standardized sustainability rating system on all supermarket products.
In Australia, meat products are only 11% of total purchases but contribute 49% of all greenhouse gas emissions. Conversely, fruit, legumes, nuts and vegetables represent 25% of all purchases, but are responsible for just 5% of emissions.
Converting greenhouse gases
Ethylene has been called “the world’s most important chemical.” It is certainly among the most produced ones, used in everything from antifreeze to plastics to polyester to vinyl. The chemical industry generated 225 million metric tons of ethylene in 2022. The conventional steam-cracking process used for its production, however, emits substantial amounts of carbon dioxide.
Now, engineers at the University of Cincinnati have found that a modified copper catalyst improves the electrochemical conversion of carbon dioxide into ethylene, creating more efficiency while simultaneously addressing climate change. The report of this breakthrough was published in the journal Nature Chemical Engineering in February 2024.
The electrocatalytic conversion of carbon dioxide produces two primary carbon products, ethylene and ethanol. The modified copper catalyst produced more ethylene; it led to an impressive 50% increase in ethylene selectivity. The next step is refining the process to make it more commercially viable. The researchers say this new technology will help make the chemical industry greener and more energy efficient. Electrifying the conversion of carbon dioxide to ethylene marks a significant stride in decarbonizing the chemical sector.
Ethylene is a fundamental building block in many products, including textiles, such as polyester. By utilizing carbon dioxide as a feedstock to make ethylene rather than depending on fossil fuels, we can effectively recycle carbon dioxide.
Recognizing a clear message
The authors of the study published in Nature say that the message is clear. While we can’t fully avoid all the overshoot on the nine planetary boundaries, we can still come much closer to living within them. In other words, the planet is seriously ill, but it’s not terminal yet.
Doing just five things could make a huge difference. Making a change in food consumption alone could prevent more than 12 million deaths per year if we transitioned to more healthy, low-emission diets.
And new ideas for mitigating climate change seem to be developed every day. Turning greenhouse gases into products like ethylene is just one of them.
Many new ideas and technologies for mitigating climate change are being developed. One of them is called Direct Air Capture, which uses large machines to suck in air, filter out the CO2, and then store it underground or use it in other applications.
So, keeping our heads up rather than down might be a more helpful mindset during this turbulent time. I think the most effective approach involves a combination of individual and collective efforts to mitigate the harms and adapt to the changes. This includes advocating for policy changes, reducing greenhouse gas emissions and preparing for the impacts of climate change.
After all, hope flows from action.
Here’s to finding your true places and natural habitats,
Candy
