Trees – natural air conditioning plants
Trees, which provide shade and act as natural air conditioners, play an important role in helping to create cities that are more resilient to extreme temperatures. This will become more so as the climate warms.
‘We have twin warming occurring,’ says Dr Helen Brown from the School of Public Health at Curtin University in Western Australia.
‘There is global warming and, in cities, the urban heat island effect. People can feel that their actions may have minimal impact on warming at a global scale, but reducing city heat is something we have direct control over.’
The urban heat island effect happens because there is less vegetation and more buildings, footpaths and roads that absorb the Sun’s heat and then radiate it back out. The annual mean air temperature of a city can be up to 3 °C higher than its surroundings. In the evening, the difference can be as high as 12 °C. These elevated urban temperatures can increase summertime peak energy demand, air conditioning costs, air pollution and greenhouse gas emissions, heat-related illness and mortality, and even affect water quality.
‘Apart from providing shade, trees cool cities through the process of transpiration, in which water is absorbed through the roots and pushed into the air via tiny pores in leaves. Think of trees as leafy, misty fans for our cities,’ Helen says.
Trees can transpire significant volumes of water: a mature tree can transpire up to 150 litres per day. In a hot, dry location such as Perth this produces a cooling effect equivalent to that of two air conditioners running for 20 hours.
‘Trees can reduce a building’s temperature by directly blocking radiation through windows and cooling the surrounding air,’ Helen says. ‘They also keep the soil cool. Evapotranspiration and shading effects can reduce air temperatures by 1 to 5 °C.
‘The cooling effects from combinations of tree planting and other vegetative cover and increased surface reflectivity have resulted in reductions of urban temperatures of between 1 and 7 °C, and of these strategies, tree planting has been found to have the most effective cooling outcome.’
Yet, as the world warms, too often urban development leads to less green space. As Helen says, ‘trees are a city’s air conditioners, so why are we pulling them out?’
Does your region have tree planting strategies?
Are there requirements for tree planting associated with new developments?
Use existing networks to communicate about change
Coasts in the future will look different to our current coasts, making it imperative for adaptation planning to involve the community to ensure people’s views are taken into account.
Community values, views and aspirations are a vital component of adaptation planning. Planning for climate change in coastal areas involves considering many different risks and options. It’s important that a diverse range of community members have input to the debate around what to do in order to ensure their views are recognised and considered.
Councils often struggle with how to involve the community in planning for sea-level rise for many reasons. Some fear a community backlash from having these conversations where there are likely to be conflicting views about what the problem is, let alone any solutions. It can be hard for council staff to know where to begin; or how to talk about highly technical and uncertain science. Plus it can be hard to get people interested in risks that seem far off into the future.
Yet where to start can be right under your nose. Any community will already have existing arrays of informal and formal groups and networks. CoastAdapt’s information manual on community engagement suggests beginning with these.
The first step in planning community engagement is to take stock of your community by mapping the existing networks and identifying the key champions – people who have a strong reach and influence in the community. You can work out how your interests intersect with theirs, as well as how you can support them (or they can support you) to engage with their group or peers.
By using existing networks as the basis for your engagement, you can build on already established communication channels: it means you go to the community rather than expecting the community to come to you. But it also requires a recognition that communication can’t be completed overnight, but may take weeks or months. Councils must be prepared to commit resources for the long term to ensure success!
How have you involved the community in adaptation planning?
Are there clear networks in your community that can be tapped into?
Climate change and coastal flooding
In February 2017, the Climate Council released a report on climate change and extreme weather events. Public interest in the findings was high due to the southeast of Australia enduring a heatwave at the time, with temperatures in the 40s.
The report noted the observed increase in heatwave length, duration and intensity; the increased intensity and occurrence of marine heatwaves causing coral bleaching; the increase in bushfire risk; and an increase in coastal flooding due to sea-level rise and storm surges.
Some of the world’s most severe climate impacts occurred in 2016, the hottest year on record globally, and extreme weather events are projected to worsen. ‘Climate change is influencing all extreme weather events in Australia,’ the Climate Council report stated. ‘All extreme weather events are now occurring in an atmosphere that is warmer and wetter than it was in the 1950s.’
Although adaptation wasn’t a focus of the 2017 report, in 2014 the Climate Council released a report on coastal flooding that summarised how to adapt to coastal flooding extremes. ‘To prepare for the sea-level rise that we can’t prevent it is essential to lower the risks of coastal flooding,’ the report stated. ‘The most effective way to deal with sea-level rise is a coordinated approach from all levels of government based on science.’
The report noted options for adapting to rising sea levels, including ‘protection’ (such as sea walls), ‘accommodation’ (such as raising footpaths), and ‘retreat’ (such as relocation of residents).
Co-author of the reports, the Climate Council’s Professor Will Steffen from the Australian National University, said an obvious adaptation approach for coastal councils is via zoning or planning for infrastructure. ‘Coastal councils need to get on top of the nature of the risks and plan accordingly,’ he said. ‘That is easier said than done, though, as restricting development along vulnerable coasts is certainly not popular in many quarters. However, a positive example is the new runway at Brisbane Airport, which has been raised to account for projected sea-level rise.’
A key message from both reports was that the impacts of extreme weather events are likely to become much worse unless global greenhouse gas emissions are reduced rapidly and deeply.
NCCARF’s CoastAdapt tool has been developed to support users to manage the risks associated with climate change. It has a wide range of data, information and guidance, including information on adaptation options, and adaptation planning.
L. Hughes and W. Steffen, 2014. Counting the Costs: Climate Change and Coastal Flooding: https://www.climatecouncil.org.au/coastalflooding
L. Hughes and W. Steffen, 2017. Cranking Up The Intensity: Climate Change and Extreme Weather Events: https://www.climatecouncil.org.au/cranking-intensity-report
Have you used CoastAdapt to determine how extreme weather and climate events may threaten your region?
What do you see as the pros and cons of protection, accommodation, or retreat?
Twitter and the Great Barrier Reef
Researchers are using new analytical techniques to discover whether social media posts can help track the health in real time of fragile ecosystems such as the Great Barrier Reef, which may help in planning adaptation strategies.
Every minute there are hundreds of thousands of tweets posted worldwide on all manner of subjects. These tweets form part of huge social media data sets that may be able to reveal insights into the health of our planet.
‘Social media represents a secret treasure for information if we know how to discover it,’ says Professor Susanne Becken, Director of the Griffith Institute for Tourism at Griffith University. ‘We use techniques including data mining, statistical modelling and machine learning to help analysis.’
‘Today all of us are generating data, and all of us are also consumers of this shared data.’
Susanne and colleagues are analysing publically available tweets sent from the Great Barrier Reef region, and searching for terms related to the reef posted internationally. During a six-month period in 2016, people posted more than 200,000 tweets from the reef. One-in-six of the tweets was geo-tagged with precise longitude and latitude data. Particularly helpful, from a scientific viewpoint, are tweets with photos.
‘Tweeted photos contain more environmental information than text, especially those that are written by non-scientists,’ Susanne says.
To supplement information from Twitter posts, the researchers use meteorological data, tourism statistics, water quality reports, and coral cover information from research agencies and from citizen science projects such as Reef Check Australia and CoralWatch.
Social media may be ‘more suited for socio-economic monitoring of residents and visitors, and can at the very least provide some form of “red flag” or early warning alert for ecosystems in distress’.
The scientists have been working with the National Environmental Science Program Tropical Water Quality Hub to develop this novel approach to improving the monitoring of the Great Barrier Reef environmental changes and quality of marine waters.
Can you identify any applications of social media analysis to support climate change adaptation in your region?
Climate change and health: the future isn’t what it used to be
Climate change could have far‐reaching consequences for human health across the 21st century. But there is at least some good news on how health systems are adapting.
‘It doesn’t take an extreme weather event to have an extreme health impact,’ said Professor Kristie Ebi, from the University of Washington, speaking at the Australian Meteorological and Oceanographic conference in Canberra in February 2017.
Kris conducts research on adaptation to climate change, including on extreme events, thermal stress, food safety and security, water-borne diseases, and vector-borne diseases. Her work focuses on understanding sources of vulnerability, and designing adaptation policies and measures to reduce the risks of climate change in a complex environment.
‘Altering weather patterns and sea-level rise may facilitate changes in the geographic range, seasonality, and incidence of some infectious diseases in some regions, such as malaria moving into highland areas in parts of sub-Saharan Africa and Asia,’ she said. ‘The geographic range of many mosquito-borne diseases is limited by temperature. Increasing temperatures with climate change may increase the population at risk when diseases emerge or re-emerge in new areas. For the mosquitoes that can carry dengue fever, Zika virus, and other viral diseases, our built environment provides many places suitable for breeding. And air travel further helps move around viruses such as dengue.’
People have a narrow capacity to adapt to high temperatures, so increasing ambient temperatures and heatwaves will increase vulnerability to heat-stress. Another consequence of climate change includes more pollen, which could exacerbate asthma and other respiratory diseases.
Changes in water availability and agricultural productivity could increase undernutrition, particularly in parts of Asia and Africa. ‘The biggest health consequence of climate change will likely be undernutrition,’ she said.
Kris said that development choices will alter the underlying vulnerability to these health risks, affecting the magnitude and pattern of impacts. ‘Vulnerability is also tied to capacity. Because vulnerability and capacity vary from place to place, the policies and programs implemented to alleviate health risks need to consider the local context.’
Kris noted good news when it comes to adaptation to increasing health risks from climate change. ‘Health services are starting to use weather and other environmental data for forecast systems,’ she said. ‘For example, early warning systems of dengue outbreaks can help prevent transmission.’
More information: https://globalhealth.washington.edu/faculty/kristie-ebi
What are the biggest threats to health in your region?
What adaptation measures are being implemented to alleviate these risks?
Who owns my risk?
One way to think about risks is through risk ownership. Risks can be owned by the organisation that owns the asset (such as a building owner), or the organisation that is responsible for managing the risk associated with that asset (such as a local council). Risks can be linear, for example the gradually increasing risk to children from exposure to lead, or non-linear, such as the sudden emergence of a new disease. Risks can be systemic, such as climate change, affecting diverse systems across multiple time frames.
Systemic risks can be contagious, that is, spread to other areas, if the scale of an event is too big for the organisation to manage, or if in managing the impact of an event unrelated assets or services are damaged. For example, a council may close a road or bridge to manage flooding risk, affecting the businesses and households who rely on that road.
The ideal is to ensure that everyone understands and accepts their risks and manages them appropriately. This is the basis of research by Celeste Young, a Collaborative Research Fellow at Victoria University.
‘Making natural disasters everyone’s business is not a short-term proposition,’ Ms Young said.
‘It requires repositioning how we view, interact with, and understand risk in both current and future contexts. Longer-term strategic thinking and clarity of risk ownership are crucial.’
‘This task is difficult because the different types of risks associated with natural hazards are systemic, resulting in interactions between seemingly unrelated risks. In many cases, risk ownership will be shared, which can make it a confusing and frustrating space for policy makers and practitioners alike.’
‘When we look at what we as both institutions and individuals value, you get an idea about what is most important. This is often the key determinant in what we spend our time and energy on. Values are important to consider when you frame communication about risk ownership. It gives you a starting point because it is much more likely that people will be willing to do something to protect what matters to them.’
Ms Young’s research found that although there was a relatively even distribution of asset ownership across institutions, ownership of risk consequence, impact and actions was primarily with local and state government.
‘What has been lacking is a clear mechanism for identifying how risk ownership can change and transfer across different temporal and geographic scales. Assigning risk ownership through a values based decision making process is a good way to start to determine who should be responsible, and if they should contribute resources to manage the risks.’
More information at: https://ajem.infoservices.com.au/items/AJEM-31-04-11#sthash.9VHBnrUZ.dpuf
Building to a warmer climate
The impacts of climate on infrastructure are changing, and will continue to change over the lifetime of infrastructure built today. Dr Tom Connor advocates that we design and build infrastructure that can be readily upgraded as the planet warms.
‘As we look ahead to developing infrastructure in Australia and in our Asia-Pacific region, we confront a challenge never faced so obviously by engineers, planners and scientists. We know that the planet’s climate will be trending one way or the other in different regions.’
Dr Connor is past president of Engineers Australia and has led flood, coastal and disaster management projects in Australia and South-East Asia, as well as undertaking sustainability and climate change initiatives over almost 30 years.
‘Without this approach, communities will be faced with increased inconvenience or risk or costs of remediation.’
All countries face the challenge of adapting infrastructure to climate change, but Australia and the Asia-Pacific region face it more acutely because of our massive coastlines, island states and high coastal population densities.
‘If Australia can develop and implement a sound and positive response to the challenge, its professional service providers will be well-placed to lead this work throughout the region,’ Dr Connor says.
‘An infrastructure guidance framework could change designers’ attitudes nationwide – from perhaps one of awareness of climate change to perhaps one of striving to understand the climate and economic reality and ensuring that the national ‘rules’ of implementation are appropriate to the circumstances.’
Decision points within each design and construction phase would allow a risk-based approach to be tailored to the specific project and location. Inputs include the design life, chosen climate change scenarios, the desired risk profile and cost analysis of outcomes of various adaptation methods.
‘Designing infrastructure for a warming planet can provide substantial scope for innovation. In the current regulatory vacuum, the reality is not being faced and wasted opportunities will return to bite us in the form of costly and disruptive retrofits in future.’
How will your agency’s building cope with climate change?
Are there changes that should be made now to prepare for a changing climate?
(This article draws on an article in the November 2016 issue of Focus, published by the Australian Academy of Technology & Engineering.)
Mexico City: and we think we have problems
Most Australians live in cities. Our four largest cities – Sydney, Melbourne, Brisbane and Perth – account for more than half the nation’s population. These coastal cities need to prepare themselves for the impacts of climate change, of which rising seas is just one. But coastal cities around the world aren’t the only ones that need to adapt to climate change.
In the middle of Mexico, high in the mountains, Mexico City has a population of over 21 million. Climate change is exacerbating some of the key challenges facing the city, as it is doing in cities throughout the world.
In a recent article, The New York Times stated, ‘Around the world, extreme weather and water scarcity are accelerating repression, regional conflicts and violence. A Columbia University report found that where rainfall declines, “the risk of a low-level conflict escalating to a full-scale civil war approximately doubles the following year.” The Pentagon’s term for climate change is “threat multiplier.”’
The article quotes Arnoldo Kramer, Mexico City’s chief resilience officer: ‘Climate change has become the biggest long-term threat to this city’s future. And that’s because it is linked to water, health, air pollution, traffic disruption from floods, housing vulnerability to landslides — which means we can’t begin to address any of the city’s real problems without facing the climate issue.’
Supplying this sprawling city with water is a challenge. Turning on the tap is a lottery for one in four residents. Some get water only once a week.
‘Climate change is expected to have two effects,’ Ramón Aguirre Díaz, Director of the Water System of Mexico City told The New York Times. ‘We expect heavier, more intense rains, which means more floods, but also more and longer droughts.’
Any cessation of rain over the city’s reservoirs would be disastrous. ‘There is no way we can provide enough trucks of water to deal with that scenario,’ said Ramón.
Climate change projections for the region make grim reading. According to a 2013 paper by Fabiola Sosa-Rodriguez from the Universidad Autonoma Metropolitana, mean temperature in Mexico is projected to rise by 2 to 4 °C from 2020 to 2080, and precipitation levels are projected to fall by up to 15 per cent in winter and up to 5 per cent in summer. The surface temperatures of the Caribbean Sea, Gulf of Mexico and the Mexican Pacific are expected to increase by 1 to 1.5 °C, ‘a situation that favours the occurrence of more frequent and intense hurricanes’.
What are the climate change projections for your region?
What adaptation measures are you planning?
To learn more about Mexico City’s problems, read the New York Times article Mexico City, Parched and Sinking, Faces a Water Crisis
Can Miami Beach hold its ground? Lessons for us all
Miami Beach in Florida is at the centre of sea-level rise and flooding issues. The large urban community experiences significant flooding every king tide. When facing the threat of increasing flood frequency, duration and height, the community is doing some things well, and others not so well. Miami Beach provides insights into how we will need to manage these issues in Australia.
Like us, Miami Beach is looking to other locations for possible solutions. For example, New Orleans is creating a $100 billion plan to help secure the city and its coastal wetlands. The population of New Orleans has shrunk significantly in recent decades, complicating matters. Fewer people now bear the financial burden of maintaining infrastructure that once supported many more.
Many think that problems can be solved through investment and engineering. For example, in the 1970s, after decades of continual flooding damage from the Kickapoo River, the army proposed to protect Soldiers Grove, Wisconsin, with a $3.5 million levee — more than three times the affected town’s asset value. The residents rejected the exercise, asking to be relocated instead. Relocation to higher ground nearby began in 1979 and was finished four years later.
Because no blueprint exists for flood-proofing cities in Florida, where low-lying areas sit atop foundations of porous limestone, Miami Beach must develop its battle plan in real time.
Miami Beach is starting to experience the dark side of risk transfer, where householders are asked to protect themselves and take care of their own property. Those in poorer communities often struggle to afford flood insurance prior to disasters or to rebuild their homes after them. The cost of insurance has been rising along with sea levels, which widens the gap between residents with a financial buffer and those at risk of losing it all. This has led to concern that instead of helping people to adapt, they are being stranded, both economically and socially.
Notwithstanding these challenges, there are some innovative ideas being discussed. One example is to design new buildings with unusually high ceilings on the ground floor so that the floor can be raised when flooding becomes frequent. Another is the city’s commitment to develop a resilience strategy that calls for a new level of collaboration across City departments and jurisdictions, with private sector, not-for-profits and community organisations. They intend to break down existing barriers at the local level, account for pre-existing resilience plans, and create partnerships, alliances and financing mechanisms that will address the resilience vulnerabilities of all city residents, with a particular focus on low-income and vulnerable populations.
CoastAdapt provides the tools to do similar planning here in Australia. It encourages a range of adaptation actions, including policy, planning, soft and hard options that are all backed up with substantial and inclusive community and industry engagement.
What is the attitude of your communities? Do they believe engineering will solve everything?
Are we stranding poorer communities by not providing adequate incentives for collaboration, insurance and improvement?
What on Earth is Blue Carbon?
Perhaps more appropriately the title of this post should read ‘What in the Ocean is Blue Carbon’, because that is where it is. Blue carbon is the carbon that is stored naturally by marine and coastal ecosystems, including by coastal ecosystems — mangroves, seagrasses and tidal marshes.
Blue carbon is important because the release of carbon into the atmosphere is a major driver of climate change, and because blue carbon ecosystems hold a LOT of carbon — a given area of mangrove forest, for example, can store up to 10 times as much carbon as the same area of land-based forest. Unlike terrestrial ecosystems, carbon stored in coastal systems can remain trapped for a long time. Low-oxygen conditions in the soil below the water can lock in carbon for centuries to millennia.
So, chopping down mangroves is a bad idea. Mangroves are exceptionally effective at absorbing carbon from the atmosphere and storing it in their extensive root systems and their soil. Once you kill those trees, or if you disturb the ground below them, their carbon is slowly released back into the atmosphere. Mangroves are so efficient at keeping carbon dioxide out of the atmosphere that when they are destroyed, they release as much as 10 per cent of all emissions worldwide attributable to deforestation – even though mangroves account for just 0.7 per cent of the tropical forest area.
In most cases, people who live on coasts are the ones who will suffer the most from mangrove destruction, because of the associated loss of biodiversity, fish breeding and coastal erosion protection.
Conservation International created ‘Blue Carbon’ to address the decline in coastal ecosystems. It is a global program working to mitigate climate change through the restoration and sustainable use of coastal and marine ecosystems.
For more information see http://thebluecarboninitiative.org
What coastal ecosystems are present in your region?
Can you find any information on changes to these ecosystems over time?