Long-abolished discriminatory lending practices in the US are still having an impact on the inequality of climate risks facing urban populations today, according to a new study.
The research, published in Nature Cities, looks at historically “redlined” neighbourhoods – those deemed highly risky for lenders, broadly due to the race and economic profile of those in the area – and compares them to neighbourhoods that were seen as less risky.
The scientists find that, across more than 200 US cities, once-redlined neighbourhoods are at higher risk of heat exposure and flooding.
Even homes just tens of metres apart have different climate risks, they find, with those located on the redlined side of a boundary at higher risk than those living on the other side of the boundary.
The lead author of the study tells Carbon Brief that the work underscores the historical legacy of planning decisions made in the last century, adding that she hopes that current policymakers can better consider the “impact of different planning policies and the unintended consequences”.
One researcher who was not involved in the study tells Carbon Brief that the work makes several significant contributions, but cautions that the authors were “pretty bold” in some of their conclusions.
‘Risky’ investments
“Redlining” refers to a discriminatory historical practice in the US, whereby neighbourhoods were graded as too “risky” for investment based on race, income levels and housing quality. These grades were used as justification for the denial of long-term mortgages and exacerbated existing racial segregation.
One of the most recognisable remnants of redlining is the set of maps produced by the Home Owners’ Loan Corporation (HOLC), established in 1933 as part of US president Franklin D Roosevelt’s “New Deal”. The HOLC refinanced foreclosed mortgages at lower interest rates with the intention of preserving and expanding homeownership.
The HOLC created maps of “riskiness” of investment in an attempt to guarantee that the loans would be paid back and that the burden on the taxpayer would be minimal.
The maps created by the HOLC classified neighbourhoods based on a four-point risk scale, with A-grades – the “best”, or least-risky, investments – outlined in green and D-grades – the most risky, termed “hazardous” – outlined in red, giving rise to the term.
B-graded neighbourhoods, outlined in blue, were termed “still desirable”, while C-graded ones, in yellow, were “declining”.
The HOLC created maps for more than 200 cities across at least 40 states. Other federal agencies and private companies later made their own “risk-assessment” maps, further cementing the practice into policy.
Although redlining was formally outlawed in 1968 by the US Fair Housing Act, the inequalities created and exacerbated by the practice persist in many places to this day, says Dr Arianna Salazar-Miranda, an urban planner and data scientist at Yale University.
Salazar-Miranda, who is the lead author of the new study, tells Carbon Brief:
“There are many social and economic dimensions for which we should be worried about this long-standing legacy of redlining.”
For example, previous research has shown that redlined neighbourhoods have lower rates of homeownership, lower credit scores and lower home values. There are also associations between historically redlined neighbourhoods and prevalence of cancer and asthma, air pollution and proximity to hazardous waste, among other dimensions of health inequality and environmental racism.
Prof Shannon Van Zandt, an urban planner at Texas A&M University, who was a reviewer of the new paper, but not involved in the study itself, tells Carbon Brief:
“Segregation is still so relevant in the experiences of families of colour and, in particular, Black or African American households, because of the very indelible lines that we literally drew [on the map].”
Climate risk
Using maps from 202 cities across the US, Salazar-Miranda and her colleagues examine the risk of heat extremes and flooding for homes in differently graded neighbourhoods. These factors, each graded on a 1-10 scale from least to most hazardous, were developed by the climate research and technology firm First Street.
The heat risk factor combines temperature and humidity to determine a “feels-like” temperature, averaged across the month of July for each location.
The flood risk factor uses flooding factors, such as rainfall and high tide levels, as well as variables that affect water runoff, including elevation and ground permeability. It also incorporates existing community flood defences. The risk is defined by both depth and likelihood of flooding.
Both the heat and flood risk scores also factor in projections of future climate change, including higher temperatures and sea level rise.
The researchers focused specifically on homes within 100 metres of a boundary between two different grades. Salazar-Miranda tells Carbon Brief:
“We’re trying to narrow down on a subset of properties that are very comparable, where they have the same underlying conditions and the only thing that changed is whether they’re on one side of the border or the other.”
The maps below show the digitised redlining map of Baltimore (left), with the colours indicating the different grades and the bold lines depicting boundaries between different grades.
On the right, a zoomed-in portion of the map shows the 100-metre buffer zones drawn around each boundary. Locations of houses are coloured according to which side of the border they fall on – grey for the lower-graded side and black for the higher-graded side.
Geographical and climatic features, such as elevation and amount of rainfall, did not vary significantly across the boundaries because the researchers were only looking at homes close to a grade boundary.
They find that, aggregated across all cities, D-graded neighbourhoods have a flood risk factor that is 0.245 points higher than A-graded ones – more than three times higher than the additional risk of a C-graded neighbourhood.
The heat risk effect is smaller, but still significant, with D-graded neighbourhoods scoring 0.033 points higher than A-graded neighbourhoods.
The chart below shows the flood and heat exposure risks for neighbourhoods graded B, C and D, relative to the average risk for A-graded neighbourhoods. While both risk factors increase as the grade decreases, the effect is much more pronounced for flood risk.
They also find that flood risk factor increases by 0.1 points, or about 5.5% on average, for homes that are on the lower-graded side of a border, as compared to homes on the higher-graded sides. For the heat risk factor, this figure is 0.011 points.
Although the absolute change in the heat risk factor is relatively small, Salazar-Miranda tells Carbon Brief that these “very small changes…can really harm your health”. She adds:
“It really depends on your pre-determinants of health – how healthy you are, how well you eat, whether you have diabetes or an underlying health condition. And we know that these are particularly worse in disadvantaged communities.”
Doing the analysis on a parcel-scale – namely, house-by-house – is one of the most significant contributions of the new work, says Prof Vivek Shandas, a professor of geography focusing on urban climate at Portland State University in Oregon, who was not involved in the new research. However, Shandas adds:
“There’s a lot that happens across 200 or 100 metres in a city…If we’re doing parcel-scale assessments, we need to get parcel-scale understanding of movement of water and the way that heat is distributed.”
‘Environmental capital’
The researchers then investigate a potential mechanism for how historical redlining could still be impacting vulnerability to current and future climate risks.
They propose that lower-graded neighbourhoods had less investment in what they call “environmental capital”, such as trees, public parks and drainage systems.
This, they say, could be due to a combination of factors: lower property values in the neighbourhoods reduces the communities’ tax income that could be invested in such projects; places with high levels of income inequality tend to have lower community engagement; and low homeownership rates can lead to reduced community investment in public goods, such as parks.
As a proxy for environmental capital investment, the authors look at four measurable factors of environmental quality: tree canopy, street-level vegetation, ground-surface perviousness and home foundation height. Tree cover and street-level vegetation can both mitigate heat risk by providing shade and inducing a cooling effect. More pervious ground surfaces allow more drainage, while higher foundations can decrease an individual home’s risk of flooding.
They find that for each measure of environmental quality, lower-graded neighbourhoods score progressively worse than higher-graded ones, as seen in the chart below.
Houses in D-graded neighbourhoods are, on average, nearly 5.7 percentage points less pervious and have 3.4 percentage points less tree cover than those in A-graded areas.
Similarly, homes on the lower-graded side of a border have lower perviousness and foundations closer to the ground level than homes on the higher-graded side, by 1.9 and 2 percentage points, respectively. Tree canopy and street-level vegetation differ between the two by 1.03 and 1.2 percentage points.
Shandas tells Carbon Brief that introducing the idea of capital into this type of analysis is “really interesting”, but the claims the authors make about their proposed mechanism are “pretty bold”. He adds:
“Each city is so unique…We can find an association, but getting a mechanism has to be [on] a case-by-case basis.”
Van Zandt adds that the redlined maps are a “good proxy”, but not necessarily the driver of inequity. The important part, she says, is “that we identified neighbourhoods that banks should not invest in – and that those patterns persist to today”.
Lived experience
Given the disparities identified in the work, Salazar-Miranda says she hopes that policymakers can incorporate this type of information into funding and other policy decisions. As an added benefit, she says, many of the investments in environmental capital – such as additional green spaces – can improve mental and physical well-being. She adds:
“One of the conversations that would be interesting, from a policy point of view, is how do we bring the types of resources to these communities that can be helpful in mitigating these environmental risks, but also from a social point of view.”
While the findings themselves are not surprising, “it’s great to have systematic assessments” and scientific evidence to back up people’s firsthand knowledge, Shandas says. He tells Carbon Brief:
“Historically disinvested parts of cities tend to be at the frontline of extreme climate events – including flooding and heat. I know the communities that live in the cities that I [have worked with] regularly have brought this up for many, many years.
“The most significant part of this study is that it’s corroborating what the lived experiences of communities have been for quite some time.”
Van Zandt adds:
“It’s not a historical study. It’s a study of what’s happening today and what’s going to continue to happen in the future.”
The post Discriminatory ‘redlining’ increases climate risk in disadvantaged US neighbourhoods appeared first on Carbon Brief.
Discriminatory ‘redlining’ increases climate risk in disadvantaged US neighbourhoods
As COP30 reaches its midway point in the Brazilian city of Belém, Carbon Brief has hosted its second “ask us anything” webinar to exclusively answer questions submitted by holders of the Insider Pass.
The webinar kicked off with an overview of where the negotiations are on Day 8, plus what it was like to be among the 70,000-strong “people’s march” on Saturday.
At present, there are 44 agreed texts at COP30, with many negotiating streams remaining highly contested, as shown by Carbon Brief’s live text tracker.
Topics discussed during the webinar included the potential of a “cover text” at COP30, plus updates on negotiations such as the global goal on adaptation and the just-transition work programme.
Journalists also answered questions on the potential for a “fossil-fuel phaseout roadmap”, the impact of finance – including the Baku to Belém roadmap, which was released the week before COP30 – and Article 6.
The webinar was moderated by Carbon Brief’s director and editor, Leo Hickman, and featured six of our journalists – half of them on the ground in Belém – covering all elements of the summit:
- Dr Simon Evans – deputy editor and senior policy editor
- Daisy Dunne – associate editor
- Josh Gabbatiss – policy correspondent
- Orla Dwyer – food, land and nature reporter
- Aruna Chandrasekhar – land, food systems and nature journalist
- Molly Lempriere – policy section editor
A recording of the webinar (below) is now available to watch on YouTube.
Watch Carbon Brief’s first COP30 “ask us anything” webinar here.
The post COP30: Carbon Brief’s second ‘ask us anything’ webinar appeared first on Carbon Brief.
Mohamed Adow is the Founder and Director of Power Shift Africa
A sobering truth hangs over the COP30 climate talks in Belém: negotiators are discussing adaptation indicators with the enthusiasm of technocrats while quietly starving frontline communities of the resources they need to survive.
The UN’s latest adaptation gap report could not be clearer. Needs are skyrocketing. Finance is collapsing. And yet the global community continues to debate how to measure progress, rather than how to enable it. They act as if weighing a cow will make it fatter, rather than giving it any food.
This contradiction exposes the heart of the climate crisis: adaptation is not merely a technical challenge; it is a political and moral one. Every finance gap is a justice gap. Behind every unmet target are farmers who cannot plant, families who cannot rebuild, and communities forced into displacement because “resilience” was promised but never delivered.
Adaptation is the difference between dignity and despair. It determines whether societies can endure rising temperatures, intensifying floods, or prolonged droughts — or whether they are pushed beyond the limits of survival.
Yet, as negotiators haggle over the Global Goal on Adaptation (GGA) and its indicators, the foundations needed to achieve these goals are crumbling. How do we talk about climate-resilient development when the means to achieve it are drying up? How do we measure resilience while draining the very resources that make resilience possible?
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At COP30, countries must resist the impulse to rush through a weak indicator framework simply to claim progress. This would give us a system that measures activity, not impact. – that measures paperwork, not protection.
Africa is championing a fit for purpose GGA, but some have misunderstood and wrongly accused it of stalling the GGA process. But Africa is not delaying adaptation work. Africa is living adaptation every day. For us, adaptation is not a choice or a policy preference or an interesting side issue. It is an existential threat that is already reshaping livelihoods, economies, and ecosystems.
Africa needs this COP to get the GGA right. What we reject is an approach that turns adaptation into an exercise in reporting rather than a vehicle for survival.
A meaningful GGA must track whether finance actually reaches those who need it, whether technologies are shared equitably, and whether vulnerable countries are being supported to build early-warning systems, climate-resilient infrastructure, water security, and heat-resilient health systems. Without this backbone of finance and technology-sharing by the rich world, adaptation indicators become little more than an empty checklist.
And this is where COP30 stands at a crossroads. If rich countries succeed in pushing through a set of indicators that sideline finance, it will confirm that the world’s poorest are once again being asked to run a race with no shoes. No community can adapt without resources. No farmer can withstand worsening heatwaves without irrigation and drought-resistant seeds. No coastal town can protect its people without early-warning systems and resilient infrastructure. To pretend otherwise is not merely flawed policy; it is a profound injustice.
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Some will argue that indicators and finance should remain separate discussions. But this is a fiction. You cannot track progress on adaptation without the means to adapt. Adaptation is where political decisions determine whether people live safely or suffer needlessly.
The world is not short of evidence of this suffering, it is short of political courage. Extreme weather displaces more than 30 million people a year, with Africa bearing the brunt. While communities rebuild with scarce resources, developed countries continue to cut aid or repackage support as loans which shackles poor countries with eye-watering debt. This does not build resilience — it entrenches vulnerability.
The Global Goal on Adaptation will become a white elephant if it is not paired with predictable, grant-based finance. Indicators that pretend adaptation is happening without resourcing it will fail the people they claim to protect. COP30 is the moment to close the distance between science and solidarity: wealthy nations must scale up adaptation finance, share technologies, and support long-term resilience planning.
Until then, the world’s most vulnerable will continue carrying the heaviest burden with the lightest support — a defining injustice of our time.
The post Global Goal on Adaptation: Weighing the cow won’t make it fatter appeared first on Climate Home News.
Global Goal on Adaptation: Weighing the cow won’t make it fatter
Last Monday, to get the COP30 agenda agreed, Brazil promised to hold consultations on four controversial issues: emissions-cutting, transparency, trade and finance. Last night, after most delegates had spent their day off exploring the Amazon, the Presidency released a five-page document summarising what was said in those consultations.
Nothing in that “summary note” has been agreed by countries. But it collects together divergent views and forms the basis of what could become a politically agreed statement (known in the jargon as a cover decision) at the end of the COP. It has three key strands on boosting climate finance, strengthening emissions reductions and tackling trade measures linked to decarbonisation.
It includes the key rhetorical messages the COP30 presidency wants to include – that this is a “COP of Truth”, multilateralism is alive (despite President Trump’s efforts to thwart climate action) and the Paris Agreement is now moving from negotiation to implementation.
On emissions-cutting and the need to raise ambition – sorely lacking after the latest round of national climate plans (NDCs) – the note includes an option to hold an annual review and explore the “opportunities, barriers and enablers” to achieve the global efforts agreed at COP28 in Dubai to triple renewable energy and double energy efficiency by 2030; accelerate action to transition away from fossil fuels; and halt and reverse deforestation. This is essentially where any reference to a roadmap to transition away from fossil fuels could be anchored.
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COP30 Bulletin Day 5: COP30 could greenlight work on a fossil fuel transition roadmap
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UN climate chief Simon Stiell tells governments “to give a little to get a lot”, as many thorny issues remain for ministers to resolve next week
The document also includes proposals to “urge” developed nations to include finance in their NDC climate plans and “encourage” all countries that have set a range of percentage emissions reductions in their NDCs – like the EU’s 66.25-72.5% – to move toward the upper end of the range.
On finance, options include a three-year work programme on provision of finance by wealthy governments and a goal to triple adaptation finance (something the least-developed countries are pushing for) or just repeating the finance goal agreed at COP29 and “noting” a new roadmap to achieve that (which rich nations very much prefer).
There are also various options for how to talk about where climate and trade overlap: an annual dialogue, roundtables, consultations, a new platform or just to keep discussing in the ‘response measures’ strand of climate talks.
Li Shuo, head of the Asia Society Policy Institute’s China Climate Hub, told Climate Home News it was highly significant that – after two years of the issue being buried in climate talks – trade has now been “anchored in the endgame of this COP”.
The various potential outcomes in the summary note could be included in existing agenda items or they could be lumped together into what is usually referred to as a cover text but the Brazilian government would likely prefer to call a “mutirão decision” or a delivery, response or global action plan.
Essentially, after governments ignored the presidency’s pleas not to add contentious items to the agenda, it looks like they could get at least some of what they want by turning those issues into the headline deal from COP30 .
At the start of the high-level segment of the conference on Monday morning, where environment ministers deliver their speeches, UN climate chief Simon Stiell urged governments “to get to the hardest issues fast”.
“When these issues get pushed deep into extra time, everybody loses. We absolutely cannot afford to waste time on tactical delays or stone-walling,” he added.
The presidency consultations on the issues in the note will continue on Monday, along with negotiations on adaptation metrics and a Just Transition Work Programme among others. The COP30 president then plans to convene a “Mutirao” meeting of ministers and heads of delegation on Tuesday “to bring together various outcomes”.
Korea joins coal phase-out coalition at COP30
As fossil fuels have grabbed headlines at COP30, major coal producer South Korea kicked off the second week of the Belém conference with an actual concrete pledge: the country will phase out most of its coal power by 2040.
Operating the seventh-largest coal fleet in the world, Korea announced on Monday that it will join the Powering Past Coal Alliance (PPCA), an initiative launched in 2017 by the UK and Canada to encourage countries to wean themselves off the planet’s largest source of emissions. Oil and gas exporter Bahrain is another new member.
Asian industrial giant Korea said that out of 62 operating coal power plants, it will commit to retiring 40 of them by 2040. The phase-out date of the remaining 22 plants “will be determined based on economic and environmental feasibility”.
Korean Minister of Environment Kim Sung-Hwan said at an event announcing the pledge that the country will play a “leading role” in the energy transition.
“South Korea is known as a manufacturing powerhouse. Unfortunately renewable energy has taken a low share in our power mix, but going forward we are determined to foster renewable energy industries,” he told journalists. “We will show the world that we can create a decarbonised energy transition.”
Asked about a fossil fuel transition roadmap – an idea floated around by many governments in Belém – Sung-Hwan said “humanity and all of the governments should work together to achieve a decarbonised green transition”, adding that “COP30 will be an important momentum”.
UK climate minister Katie White said Korea was taking an “ambitious step”, and that they can “reap the rewards that we are seeing from our own clean energy transition”.
Korea is a major importer of oil and gas. Domestically, it has historically relied on coal for electricity, but the country’s production of the fossil fuel has decreased steadily by 86% in the last 25 years, according to the International Energy Agency (IEA). Their nuclear fleet, on the other hand, has nearly doubled in the same time period.
The post COP30 Bulletin Day 7: Brazil outlines options for a possible deal in Belém appeared first on Climate Home News.
COP30 Bulletin Day 7: Brazil sets out options to reach a deal in Belém
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