What did the latest IPCC report on climate change actually say?

Climate protesters in Washington D.C., 2017. Image: Getty.

The world’s climate scientists have spoken: if we want to limit human-induced global warming to 1.5℃ we probably can. But it will be tough, given where we’re starting from.

That’s the conclusion of a new report by the UN’s Intergovernmental Panel on Climate Change (IPCC). The focus on 1.5℃ is the result of years of international negotiation. Starting in 1994, a central aim of the UN’s climate change efforts (the Framework Convention on Climate Change, or UNFCCC) was to stabilise greenhouse gas concentrations at a level that would “prevent dangerous anthropogenic interference with the climate system”. Much was written on what this meant, particularly the word “dangerous”.

Negative impacts of climate change occur on a continuum, and defining a point at which climate change becomes dangerous is difficult and contentious. On the other hand, climate change negotiations are difficult without some target to work towards.

Fifteen years later, the UNFCCC’s Copenhagen Accord introduced a 2℃ target, and its 2015 Paris Agreement was even more specific: it “aims to strengthen the global response to the threat of climate change... by holding the increase in... temperature to well below 2℃ above pre-industrial levels and pursuing efforts to limit the... increase to 1.5℃”.

The IPCC provides scientific advice to the UNFCCC, which makes policy, and the IPCC itself has never stated a temperature target. It does however list climate change risks using five “reasons for concern”. These include impacts such as “unique and threatened ecosystems and cultures” (such as coral reefs) and “extreme weather events”, each of which is rated on a scale from “undetectable” to “very high”. The IPCC’s most recent (2014) Fifth Assessment of the scientific evidence found that at around 1.5℃ warming there was a transition from moderate to high risk for threatened ecosystems and cultures and for extreme weather events. Thus there is consistency between the Paris and IPCC assessments.

The Paris Agreement asked the IPCC to report on the impacts of global warming of 1.5℃, and this new publication is the result. Its tone is not “we must avoid 1.5℃ warming”, as you might think from many commentators, but more “if we want to avoid 1.5℃ warming, this is what must be done”. The report contrasts the impact of 1.5℃ and 2℃ warmings, giving information on what would be gained by the extra effort needed to limit warming to 1.5℃.

As the IPCC’s reports are largely based on a critical assessment and synthesis of published scientific papers, many of its latest conclusions are unsurprising. There are many well recognised uncertainties in understanding climate change - for instance, even if we set a course aiming to hit 1.5℃ (which is mostly determined by future CO₂ emissions), we could end up hitting, say, 1℃ or 2℃ instead. The report provides uncertainty ranges in its estimates and confidence levels, based on expert judgement.


The new report tells us that human activity has already caused about 1℃ of global warming, while at the present rate of warming (0.2℃ per decade) we’ll hit 1.5℃ by about 2040. National pledges made as part of the Paris Agreement still mean we are on course for warming of about 3℃ by 2100, meaning four of the five “reasons for concern” would then be in the high to very-high risk category.

Achieving the 1.5℃ target will require anthropogenic CO₂ emissions to decline by 45 per cent by 2030 (relative to 2010). By 2050, they will need to reach “net zero” - any further CO₂ emissions due to human activity would then have to be matched by deliberate removal of CO₂ already in the atmosphere, including by planting trees. Net zero would have to occur by around 2075 to meet a 2℃ target.

Many illustrations are given for the difference between 1.5℃ and 2℃ worlds. At 1.5℃, summertime Arctic sea ice is projected to disappear once per century, compared to once per decade at 2℃; 8 per cent of plants that have been studied would lose half their climatically-suitable area, compared to 16 per cent; sea level rise would be 10cm less (with 10m fewer people impacted at today’s population levels); and while coral reefs might decline by a further 80% at 1.5℃, they could virtually disappear at 2℃.

The report identifies various routes by which emissions cuts would limit warming to 1.5℃; each makes assumptions about future changes in, for example, economic strategy, population growth and the rate at which low carbon energy is adopted. The IPCC recognises the challenges are “unprecedented in scale” but notes, for example, “the feasibility of solar energy, wind energy and electricity storage mechanisms have substantially improved over the past few years”.

The report is sensitive to the fact that changes required to meet 1.5℃ must be consistent with the UN’s wider sustainable development goals. Limiting climate change will help meet goals associated with health, clean energy, cities and oceans. But there are potential negative impacts on others (poverty, hunger, water, energy access) “if not carefully managed”.

So where next? Of course, the conclusions will be widely debated at many levels, but eyes will be on the UNFCCC’s response at its next meeting, in Katowice, Poland, in early December.

The Conversation

Keith Shine, Regius Professor of Meteorology and Climate Science, University of Reading.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 
 
 
 

How can cities become more bike friendly? The Netherlands offers useful lessons

(Aurore Belot/AFP via Getty Images)

It might seem like cycling is in the DNA of the Netherlands, a country where even the prime minister takes his bicycle to work. But the Dutch haven’t always lived as one with their bikes. In the Amsterdam of the early 1970s, cars were considered the wave of the future. They can be seen filling up squares and streets in historical photographs, and killed an average of over two Amsterdammers per week, including many children.

It is nothing more than an “accident of history” that the Netherlands embraced cycling, says Marco te Brömmelstoet, the director of the Urban Cycling Institute in Amsterdam and a man better known as the city’s cycling professor. Today’s bike rider’s paradise was created after parents and activists took to the streets to protest “child murder” by car. A Saudi oil embargo, rising gas prices, concerns about pollution and anger about the destruction of entire neighbourhoods to build motorways did the rest. 


Amsterdam, 1958. Not a cyclist's paradise. (Keystone/Getty Images)

What’s important about this history is that it can be replicated in other cities, too. Of course, the Netherlands has certain advantages – it’s flat as a pancake, for example. But in the eyes of traffic reformers, the rise of e-bikes (and even cargo bikes) means there’s no excuse for prioritising cars everywhere. 

So how can cities, flat or not, follow Amsterdam’s path to creating places where cycling is a pleasant, safe and common way to get around? The Dutch have some tips. 

Separate bikes from car traffic

Any city could start painting dedicated bike lanes on the streets. But in the Netherlands, those white marks indicating space for cyclists are considered just a minor first step. 

“A line on the road is not enough. Motorists will ignore it,” says Frans Jan van Rossem, a civil servant specialising in cycling policy in Utrecht. If other cities want their residents to choose bikes instead of cars when dodging pandemic-era public transport, protecting them from fast-moving car traffic must be the priority, Van Rossem says. 

The Dutch research institute CROW developed a widely praised design manual for bicycle infrastructure, full of tips for creating these protected lanes: A row of vertical white posts or a curb can serve as a physical separator, for example. Still, cyclists tend to feel safest in a "solitary" path, separated from the road by grass, trees, or an elevated concrete island. 

“The main bottleneck, the main reason why people don’t cycle, is that they don’t feel safe,” Van Rossem notes. “To start, construct separate paths.”

Turn those bike paths into a network

Many cities may have some bike lanes on some streets, but leave cyclists to roll the dice everywhere else. Will conditions still be safe when they turn left or right? Often they have to continue their way without any protected facilities for cyclists. 

“In many cases, cities take fast action, without thinking it through very well,” says Lucas Harms. He leads the Dutch Cycling Embassy, a partnership between the Dutch government and several companies, which promotes Dutch bike knowhow globally. “Don’t build small pieces of bike lane from nothing to nowhere. Think about a network of cycling infrastructure.” 

Utrecht aims to have cyclists within 200 to 300 metres of a connected path anywhere in the city, Van Rossem says. Avoid constructing those paths in sketchy industrial areas, he warns. “A connection through an unattractive area may be fast, but won’t be used a lot.”

Embrace the ‘fietsstraat’, a street where bikes come first


On some streets, drivers have to give up their privileges. (Rick Nederstigt/AFP via Getty Images)

A peculiar Dutch invention called "fietsstraat" (cycling street) holds strong potential for the rest of the world, Kevin Krizek says. He’s a transportation professor from Colorado who spent three years at Radboud University in Nijmegen. 

On cycling streets, cars are “guests”, restricted by a speed limit of 30 kilometres per hour. Drivers are not allowed to pass, so cyclists comfortably dominate the road. In the Netherlands the fietsstraat is usually paved with red asphalt, to resemble a bike path and notify drivers of their secondary status. But creating a cycling street can be easy. “All you need to do is put signs at intersections,” Krizek says. The effect is revolutionary in his view. Drivers have to give up their privileges, and cyclists can take the lead. 

Some Dutch traffic experts worry the cycling street won’t work if a city doesn’t also have a robust cycling culture. In the Netherlands, drivers are aware of the perils of urban cycling because they too use bicycles. Moreover, Dutch cities use sophisticated “circulation plans” to direct cars away from city centres and residential areas, onto a few main routes. 

Without “calming” traffic this way, the cycling street could be a step too far, Harms says. “In a city like New York, where all roads are equally accessible and full, it’s better to separate bicycles and cars,” he says.

Redesign intersections for cyclists' safety

If cyclists have to cross intersections “at the mercy of the Gods”, you’re not there yet, says Harms. When he travels abroad, he often finds clumsily designed crossings. As soon as cars turn, cyclists may fear for their lives. 

Harms recommends placing physical barriers between cars and bikes in places where they must cross. The Dutch build elevated islands to direct traffic into separate sections. The golden rule: cars wait behind bicycles. That way, drivers can see cyclists clearly at all times. Barriers also force Dutch cyclists to turn left in the safest way possible. They cross the street first and wait for their turn again before making their way left.

“You can create that with simple temporary measures,” Harms says. Planters work fine, for example. “They must be forgiving, though. When someone makes a mistake, you don’t want them to get seriously injured by a flower box’s sharp edge.”

Professor Krizek points out how the Dutch integrated cycling routes into roundabouts. Some are small; some are big and glorious, like the Hovenring between Eindhoven and Veldhoven, where cyclists take a futuristic-looking roundabout lifted above the highway. Most of those traffic circles move high volumes of cars and cyclists through intersections efficiently and safely. For a simpler solution, the Dutch manual suggests guiding cyclists to quieter streets – crossing a block up or down may be safer. “Nobody knows how to do intersections better than the Dutch,” says Krizek. 

Ban cars, or at least discourage them


A man rides down from a three-level bicycle parking garage near Amsterdam's main train station. (Timothy Clary/AFP via Getty Images)

The quickest, most affordable way to make a city more bikeable is to ban cars, says Ria Hilhorst, cycling policy advisor for the City of Amsterdam. It will make streets remarkably safe – and will most likely enrage a significant amount of people. 

Amsterdam doesn’t outlaw cars, but it does deliberately make their owners feel unwelcome in the historic city’s cramped streets. Paid parking is hugely effective, for example. Many car owners decide to avoid paying and use bicycles or public transportation for trips into the city. Utrecht, meanwhile, boasts the world’s largest bicycle parking garage, which provides a dizzying 12,500 parking spots.

To further discourage drivers from entering the city’s heart, Amsterdam will soon remove more than 10,000 car-parking spaces. Strategically placed barriers already make it impossible to cross Amsterdam efficiently by car. “In Amsterdam, it is faster to cross the city on a bike than by car,” Harms says. “That is the result of very conscious policy decisions.”

Communicate the benefits clearly

Shopkeepers always fear they will lose clients when their businesses won’t be directly accessible by car, but that’s a myth, says Harms. “A lot of research concludes that better access for pedestrians and cyclists, making a street more attractive, is an economic boost.”

Try replacing one parking space with a small park, he recommends, and residents will see how it improves their community. Home values will eventually rise in calmer, bike-friendlier neighbourhoods without through traffic, Van Rossem says. Fewer cars mean more room for green spaces, for example.

“I often miss the notion that cycling and walking can contribute a lot to the city. One of the greatest threats to public health is lack of exercise. A more walkable and bikeable city can be part of the solution,” says Ria Hilhorst. “But in many countries, cycling is seen as something for losers. I made it, so I have a car and I’m going to use it, is the idea. 

“Changing this requires political courage. Keep your back straight, and present a vision. What do you gain? Tranquility, fewer emissions, health benefits, traffic safety, less space occupied by vehicles.” 

Again, she points to Amsterdam’s history. “It is possible; we were a car city too.”

Karlijn van Houwelingen is a journalist based in New York City.