Threats of sea level rise, security implications of climate change

An Otago University research paper warns that the effects of sea level rise will impact most on vulnerable people (that’s likely), while a Defence Assessment “identifies climate change as one of the most significant security threats of our time”.

While it is still debatable how much the sea level is likely to rise there is no doubt it has been (slowly) rising over the past half century.

Some still say nothing should be done about climate change, but academics and officials are at least thinking and writiing reports about possible effects and implications.

RNZ:  Sea level rise threatens major NZ infrastructure – report

The burden of sea-level rise will weigh on the most vulnerable unless a new approach is developed and legislated, a new report says.

The paper, written by University of Otago Associate Professor Lisa Ellis, is part of research from the Deep South National Science Challenge. It looks at how New Zealand distributes the risks of sea-level rise.

It proposes an “ethically robust” policy to adapt to the risks of climate change.

Tens of thousands of buildings, infrastructure including airports, railways, and roads, and more than 100,000 residents are at risk of serious loss and damage associated with sea-level rise within the next century.

Dunedin’s airport is low lying, and has already flooded.

Image result for dunedin airport flooded

Flooding on the Taieri Plain, 1980 (airport in lower half of photo)

Rising sea levels and predicted more rain and storms would make this sort of ‘100 year flood’ more common.

South Dunedin in also low lying (it is reclaimed swamp) and has flooded in recent years.

Prof Ellis said sea-level rise was entirely predictable but if New Zealand was proactive about adaptation to climate change, peoples’ wellbeing would not be threatened.

But she said it was possible existing inequality would be exacerbated and the cost of adapting to climate change would rise if the status quo remained.

Her report recommended a government resource about adapting to sea-level rise nationwide, so community resilience did not vary with ratepayers’ ability to pay.

At local level the public should be engaged as early and deeply as possible.

Also from RNZ:  Sea level rise threatens major NZ infrastructure (audio)

Local Government New Zealand: Young and vulnerable shouldn’t shoulder sea-level rise burden

A report released this morning by the Deep South National Science Challenge supports LGNZ’s call for a national framework to deal with sea-level rise, saying that New Zealand’s youngest and most vulnerable are at risk of shouldering the burden if we don’t act now.

“Preliminary findings from our upcoming sea-level rise report shows that billions of dollars of local government roading, water and public transport infrastructure is at risk from as little as half a metre of sea-level rise.  That’s not including private buildings and houses, including potentially billions of dollars in residential real estate,” says LGNZ President Dave Cull.

“Areas like South Dunedin illustrate just how difficult it is to adapt to climate change without hitting lower socio-economic families in the pocket, so we need a national plan that doesn’t leave anyone behind.”

“Local government stands alongside our communities on the front line in the fight against climate change, but we can’t do it alone – we need central government to set stronger, national rules around risk and liability to property owners in the path of sea-level rise.”

Research from NIWA reveals that sea level rise in New Zealand has increased from 1.7mm a year over the past century, to 4.4mm a year since 1993, which is higher than the global average.  In combination with more severe weather events, storm surges and king tides, sea-level rise presents a huge problem for coastal businesses and residents.

“We need to treat sea-level rise the way we do earthquakes, and that requires a national strategy that gives councils a stronger platform on which to make decisions about building in high-risk areas.”

Ministers of Defence, Climate Change: Defence Assessment on Climate Change and Security Released

Minister of Defence Ron Mark and Minister for Climate Change James Shaw have today released a Defence Assessment on the security implications of climate change.

The Climate Crisis: Defence Readiness and Responsibilities explores the implications of climate change for New Zealand Defence Force operations.

It identifies climate change as one of the most significant security threats of our time, and one that is already having adverse impacts both at home and in New Zealand’s neighbourhood.

“This Government is committed to ensuring New Zealand does its part to address climate change,” says Ron Mark.  “This means both contributing to mitigating climate change itself, and working with our international partners to respond to the intensifying impacts climate change will bring.

“Earlier this year the Government’s Strategic Defence Policy Statement recognised climate change will have a big impact on Defence operations, particularly in the Pacific.

“It proceeded to highlight that disruptive weather patterns are causing an increased frequency and intensity of weather extremes such as cyclones, rainfall events, droughts, and flooding from sea level rise. In addition, the state of the Southern Ocean is changing, meaning our current vessels are getting close to the limits of being able to operate safely.

“Therefore it stands to reason that we needed to look deeper in order to better understand the social and security implications of climate change, and what our Defence Force will face when it responds to these weather events.

“The Coalition Government already has a work programme underway to help alleviate the effects of climate change.  This includes re-energised Pacific policy settings, the development of a new climate change law, and the commitment to make 100 per cent of New Zealand’s electricity renewable by 2035,” says James Shaw.

The assessment has been produced by the Ministry of Defence in consultation with the New Zealand Defence Force, other New Zealand agencies, Pacific partners and academics.

https://www.defence.govt.nz/publications/publication/the-climate-crisis-defence-readiness-and-response

There is certain to be a lot of ongoing talk about the possible effects and implications of climate change and sea level rise, but it is yet to be seen whether there will be any significant action.

Global and Regional Sea Level Rise Scenarios

The National Oceanic and Atmospheric Administration has released a report on Global and Regional Sea Level Rise Scenarios for the United States.

This includes a revised extreme level of rise of 2.5 meters by 2100, 0.5 more than used at Paris in 2012.


EXECUTIVE SUMMARY

The Sea Level Rise and Coastal Flood Hazard Scenarios and Tools Interagency Task Force, jointly convened by the U.S. Global Change Research Program (USGCRP) and the National Ocean Council (NOC), began its work in August 2015. The Task Force has focused its efforts on three primary tasks:

1) updating scenarios of global mean sea level (GMSL) rise,

2) integrating the global scenarios with regional factors contributing to sea level change for the entire U.S. coastline, and

3) incorporating these regionally appropriate scenarios within coastal risk management tools and capabilities deployed by individual agencies in support of the needs of specific stakeholder groups and user communities.

This technical report focuses on the first two of these tasks and reports on the production of gridded relative sea level (RSL, which includes both ocean-level change and vertical land motion) projections for the United States associated with an updated set of GMSL scenarios.

In addition to supporting the longer-term Task Force effort, this new product will be an important input into the USGCRP Sustained Assessment process and upcoming Fourth National Climate Assessment (NCA4) due in 2018.

This report also serves as a key technical input into the in-progress USGCRP Climate Science Special Report (CSSR). In order to bound the set of GMSL rise scenarios for year 2100, we assessed the most up-to-date scientific literature on scientifically supported upper-end GMSL projections, including recent observational and modeling literature related to the potential for rapid ice melt in Greenland and Antarctica.

The projections and results presented in several peer-reviewed publications provide evidence to support a physically plausible GMSL rise in the range of 2.0 meters (m) to 2.7 m, and recent results regarding Antarctic icesheet instability indicate that such outcomes may be more likely than previously thought.

To ensure consistency with these recent updates to the peer-reviewed scientific literature, we recommend a revised ‘extreme’ upper-bound scenario for GMSL rise of 2.5 m by the year 2100, which is 0.5 m higher than the upper bound scenario from Parris et al. (2012) employed by the Third NCA (NCA3).

In addition, after consideration of tide gauge and altimeter-based estimates of the rates of GMSL change over the past quarter-century and of recent modeling of future low-end projections of GMSL rise, we revise Parris et al. (2012)’s estimate of the lower bound upward by 0.1 m to 0.3 m by the year 2100.

This report articulates the linkages between scenario-based and probabilistic projections of future sea levels for coastal-risk planning, management of long-lived critical infrastructure, mission readiness, and other purposes. The probabilistic projections discussed in this report recognize the inherent dependency (conditionality) of future GMSL rise on future greenhouse-gas emissions and associated ocean-atmosphere warming.

In recognition of the different time horizons of relevance to different decision contexts, as well as the long-term GMSL rise commitment (lagged GMSL response) from on-going increases in oceanatmosphere warming, GMSL rise and associated RSL change are quantified from the year 2000 through the year 2200 (on a decadal basis to 2100 and with lower temporal frequency between 2100 and 2200).

The 0.3 m-2.5 m GMSL range for 2100 is discretized by 0.5-m increments and aligned with emissionsbased, conditional probabilistic storylines and global model projections into six GMSL rise scenarios: a Low, Intermediate-Low, Intermediate, Intermediate-High, High and Extreme, which correspond to GMSL rise of 0.3 m, 0.5 m, 1.0 m, 1.5 m, 2.0 m and 2.5 m, respectively.

These GMSL rise scenarios are used to derive regional RSL responses on a 1-degree grid covering the coastlines of the U.S. mainland, Alaska, Hawaii, the Caribbean, and the Pacific island territories, as well as at the precise locations of tide gauges along these coastlines.

These scenario-based RSL values fill a major gap in climate information needed to vii support a wide range of assessment, planning, and decision-making processes.

GMSL was adjusted to account for key factors important at regional scales, including:

1) shifts in oceanographic factors such as circulation patterns;

2) changes in the Earth’s gravitational field and rotation, and the flexure of the crust and upper mantle, due to melting of land-based ice; and

3) vertical land movement (VLM; subsidence or uplift) due to glacial isostatic adjustment (GIA, which also changes Earth’s gravitational field and rotation, as well as the overall shape of the ocean basin), sediment compaction, groundwater and fossil fuel withdrawals, and other nonclimatic factors.

Key findings include:

● Along regions of the Northeast Atlantic (Virginia coast and northward) and the western Gulf of Mexico coasts, RSL rise is projected to be greater than the global average for almost all future GMSL rise scenarios (e.g., 0.3-0.5 m or more RSL rise by the year 2100 than GMSL rise under the Intermediate scenario).

● Along much of the Pacific Northwest and Alaska coasts, RSL is projected to be less than the global average under the Low-to-Intermediate scenarios (e.g., 0.1-1 m or less RSL rise by the year 2100 than GMSL rise under the Intermediate scenario).

● Along almost all U.S. coasts outside Alaska, RSL is projected to be higher than the global average under the Intermediate-High, High and Extreme scenarios (e.g., 0.3-1 m or more RSL rise by the year 2100 than GMSL rise under the High scenario).

Finally, the consequences of rising RSL are presented in terms of how the frequency of moderate-level flooding associated with a NOAA coastal/lakeshore flood warning of a serious risk to life and property may change in the future under the sea level scenarios.

The elevation threshold used to classify such events by NOAA on their tide gauges varies along the U.S. coastline, but in general it is about 0.8 m (2.6 feet) above the highest average tide and locally has a 20% annual chance of occurrence.

For example, using the flood-frequency definition, we find at most locations examined (90 cities along the U.S. coastline outside of Alaska) that with only about 0.35 m (<14 inches) of local RSL rise, annual frequencies of such disruptive/damaging flooding will increase 25-fold by or about (±5 years) 2080, 2060, 2040 and 2030 under the Low, Intermediate-Low, Intermediate and Intermediate High subset of scenarios, respectively.

https://tidesandcurrents.noaa.gov/publications/techrpt83_Global_and_Regional_SLR_Scenarios_for_the_US_final.pdf

Larsen C ice shelf rift grows

It looks like the Larsen C ice shelf will break off in West Antarctica soon (in the next few months) after a sudden extension of the rift by 18 km in December, leaving just 20km holding 5000 square kilometre shelf on.

93282005_rift_figure_narrow_jan2017_large

Larsen A broke off in 1995, and Larsen B broke off in 2002.

This is what happens to ice shelves over time. There is no way of knowing if the process is being sped up by climate change or not.

RNZ: Huge iceberg poised to break off Antarctica

A long-running rift in the Larson C ice shelf grew suddenly in December and now just 20km of ice is keeping the 5000 sq km piece from floating away.

…in December the speed of the rift went into overdrive, growing by a further 18km in just a couple of weeks. What will become a massive iceberg now hangs on to the shelf by a thread just 20km long.

“If it doesn’t go in the next few months, I’ll be amazed,” project leader Prof Adrian Luckman, from Swansea University, told BBC News.

While very interesting this isn’t abnormal.

NZ Antarctic Research Institute director Gary Wilson said this was a fairly normal process for ice shelves to carve off when they came into enough interaction with storm swells.

He said the questions would be whether it would cause warmer water to get further under the ice shelf, and whether it would allow the storm swells to break up further back.

Larsen C is about 350m thick and floats on the seas at the edge of West Antarctica, holding back the flow of glaciers that feed into it.

As it floats on the sea, the resulting iceberg from the shelf will not raise sea levels. But if the shelf breaks up even more, it could result in glaciers that flow off the land behind it to speed up their passage towards the ocean. This non-floating ice would have an impact on sea levels.

According to estimates, if all the ice that the Larsen C shelf currently holds back entered the sea, global waters would rise by 10cm.

That’s likely to be a long term thing, if it happens. Sea levels have risen since the last ice age.

post-glacial_sea_level

What has changed recently is the huge increase in population and the establishment of settlements in low lying areas.

Understanding sea level

Predictions on sea level change range from negligible and nothing to worry about to potentially catastrophic for many major population areas.

We are currently in an interglacial period. In the last interglacial period about 125,000 years ago sea levels rose to several metres higher than they are now, and that was without the degree of fossil fuel emissions we have now.

Even with natural variations there is cause for concern. If emissions trigger a massive icecap melt it could be calamitous with current low altitude population densities.

National Geographic: Why the New Sea Level Alarm Can’t Be Ignored

The physics of ice predicts that sea level will rise twice as much by the end of the century as previously estimated.

There are days when even a born optimist starts to waver in his conviction. The release of a new study projecting that sea level could rise between five and six feet by 2100—when many children born today will still be alive and have been forced to move inland—made Thursday one of those days.

Some 125,000 years ago, for instance, Earth was in an interglacial period, like the one we’re in now, a warm interlude between 100,000-year-long ice ages. The temperature then was about the same as it is today, a degree or two warmer at most. But the best evidence indicates sea level was at least 20 feet higher—which in itself is disconcerting, suggesting as it does that we might be poised on the brink of something big.

20 feet is about 6 metres.

The Thwaites glacier in West Antarctica is far more massive than the Jakobshavn glacier. According to another alarming study published last year, it has already become unmoored from the 2,000-foot high submarine ridge that holds it in place. If it begins to retreat down the long slope toward the center of the ice sheet, the cliffs it would produce would be far taller than the Jakobshavn one—and probably not stable.

“Then, rather than break-wait-wait-wait-break, it might switch to break-wait-break or just break-break-break,” Alley says.

That’s what Deconto and Pollard’s model suggests could start happening to the West Antarctic Ice Sheet by the second half of this century, if we don’t curb our carbon emissions: Just break-break-break.  And by 2100, when sea level had risen five or six feet, the breaking would have only just begun.

So there are real risks. We just don’t know how big the risks are – and we may not know until it’s too late, maybe not for us but for our children and grand children.

Sea level measurements and predictions are very complex.

NASA has set up a website on Understanding Sea level

NASA keeps track of sea level change and its causes from space. Find out more about how NASA satellite observations help our understanding of this complex topic.

Learn more about how models forecast the future of sea level, and how different components contributing to sea level change are predicted to evolve over time.

That looks like an excellent resource on sea levels.

Preparing for rising seas

It’s widely accepted that climate change and sea level rise are likely to be a reality in the near future, with the only uncertainties being how much, how soon and how much we can or are willing to do about it.

A report from the Commissioner of the Environment:

Preparing New Zealand for rising seas: Certainty and Uncertainty (PDF)

From the Overview (edited):

The subtitle of this report is ‘Certainty and Uncertainty’. It is certain that the sea is rising and will continue to do so for centuries to come. But much is uncertain – how rapidly it will rise, how different coastal areas will be affected, and how we should prepare. And we do need to prepare. After all, as an article in the New York Times put it this year: “Human civilization is built on the premise that the level of the sea is stable, as indeed it has been for several thousand years”.

The rising sea will lead to flooding on low-lying land near the coast, erosion of many beaches and ‘soft’ cliffs, and higher and possibly saltier coastal groundwater.

  • Flooding of coastal areas will become more frequent, more severe, and more extensive.
  • Erosion – a long-familiar problem around some of our coasts – will become more widespread.
  • Groundwater linked to the sea will rise and possibly become brackish.

However, care must be taken with generalisations. Local features matter a great deal.

For instance, open unsheltered coasts experience the full force of the sea, so are more vulnerable to flooding than enclosed bays. Beaches regularly replenished with sediment are less prone to erosion. Groundwater problems are most likely to occur in land that has been reclaimed from the sea.

Natural hazards like earthquakes, volcanic eruptions, and river floods can happen at any time. In contrast, sea level rise is incremental and inexorable – its effects on our coast will unfold slowly for a period before accelerating. We must start planning, but there is enough time to plan and do it well.

Certainly the world, including New Zealand, needs to act urgently to reduce carbon dioxide and other greenhouse gas emissions. However, during this investigation, I have realised that the same urgency does not apply to much of the planning we need to do for sea level rise. Indeed, haste can be counter-productive.

Because current government policy on sea level rise emphasises the need to take a ‘precautionary approach’, technical analysts have been embedding ‘precaution’ into coastal risk assessments to varying degrees. This takes various forms such as assuming ‘high end’ amounts of sea level rise.

One particular need is to avoid referring to ‘one-in-50 year’ or ‘one-in-100 year’ events. Not only is it difficult to understand, it is not a stable measure over time. The ‘high water’ caused by a storm surge riding on top of a king tide that is now expected to occur once every 100 years will occur more and more often as the sea rises.

There are aspects of planning for sea level rise that should be done with some urgency. One is concerned with the granting of consents for greenfields development. New suburbs and the expensive infrastructure they require should be viewed as long-term investments. We now see building new suburbs on land prone to liquefaction in much of the country as foolish. We should see allowing new subdivisions on vulnerable coastal land as equally foolish.

Another is the need to establish much more extensive monitoring systems. This is required before we can develop better models of shoreline erosion and accretion. Such monitoring is also needed for adaptive management, which will be the appropriate strategy in many cases. Adaptive management involves staging interventions over time as trigger points are reached.

Unusually, one of my recommendations in this report is to the Minister of Finance. It is not too soon to begin to consider the fiscal implications of sea level rise. Both central and local government will face increasing pleas for financial assistance – whether it be for building a seawall, maintaining an eroding coastal road, or, as will eventually happen, moving entire communities further inland.

What the world, including our small country, does now will affect how fast and how high the sea rises.

That’s signed by Dr Jan Wright, Parliamentary Commissioner for the Environment.

The detailed report: Preparing New Zealand for rising seas: Certainty and Uncertainty

It’s difficult to know what can be done to mitigate possible problems and what might be futile.

But it’s become increasingly clear that we should be increasing our awareness and caution about possible changes.

Ignoring it and doing nothing is not an option.

One positive aspect is that whatever we do in response to growing concerns is not going to do any harm and will likely benefit us and our planet, regardless of how accurate predictions are of impending problems.

We should be more aware  and care better for our planet, no matter what the climate does.

 

Sea level rise may be accelerating

Climate change predictions are not fixed, they keep needing to be adapted as more research results become known.

A new Australian study appears to explain a previous puzzle. Radio NZ reports in Sea level rise accelerating – study.

Satellite data dating back to 1993 appeared to show sea level rise accelerating in the 1990s and then slowing over the following decade.

But a new study claims that was incorrect due to early inaccuracies.

Sea level rise accelerated faster in the past two decades than it did for the majority of the 20th century according to a new study.

The report, published in the journal Nature Climate Change, corrected an anomaly that had puzzled the scientific community for years.

Satellite data dating back to 1993 appeared to show sea level rise accelerating in the 1990s and then slowing over the following decade.

Over the past five years, researchers from the University of Tasmania have been using tide gauges to check the satellite data.

Lead researcher Christopher Watson said they now thought they had the answer.

“Now, once we make a correction for how much land motion is at the tide gauge, or how much it’s moving up and down, we’re able to get a better picture of the really small inaccuracies within the altimeter record.”

He said the study suggested satellites marginally overestimated the rate of sea level rise in the first six years and that distorted the long-term picture.

Revised data suggested the rate of rise actually increased over the past 20 years.

“What we can see here is sea level clearly rising over the 20-year satellite altimeter record with acceleration in the record,” said Dr Watson.

If this is accepted then a few climate models may need to be adjusted.

Report co-author John Church, a fellow of Australia’s CSIRO science agency, said sea levels were predicted to rise by up to 98 centimetres in the next 85 years.

He said that would affect more than 150 million people living in low-lying coastal communities.

“If we have major mitigation, then we can limit that rise to be somewhere between 30 and 60 centimetres during the 21st century,” he said.

Two things are certain about climate change – the research will continue and the arguments will continue.

Nature Climate Change article: Unabated global mean sea-level rise over the satellite altimeter era

Whale Oil cites a social anthropologist as a climate change expert

Cameron Slater continues his anti-climate change agenda at Whale Oil, yesterday posting TURNS OUT THE POLES AREN’T MELTING, NOT THAT OUR MEDIA OR GOVERNMENT WILL SAY ANYTHING.

He quotes from an article featuring claims by Dr Benny Peiser from Global Warming Policy Forum (GWPF). Does Peiser sound like a well educated climate scientist?

Sourcewatch claims:

Benny Peiser (b. 1957) is a UK social anthropologist and AGW denier listed among the Heartland Institute “Global warming experts” despite having no evident expertise in climate science or policy.

Peiser was educated in West Germany and studied political science, English, and sports science in Frankfurt.

Although Peiser is described by Local Transport Today as a ‘climate policy analyst’, it is unclear what academic expertise Peiser brings to bear on his climate policy analyses.

According to a search of 22,000 academic journals, Peiser has published 3 research papers in peer-reviewed journals: Sports Medicine, 2006; Journal of Sports Sciences (2004); and, Bioastronomy 2002: life among the stars (2004). None of these studies are related to human-induced climate change.

Peiser also runs CCNet (network) to counter ‘doomsday scaremongering about the possible effects of climate change’.

Slater would ridicule someone with Peiser’s lack of relevant scientific credentials if they were on the other side of the argument. Ironically he concludes:

I can’t wait for the global fraud trials to begin…if you did in business what these so-called scientists have done you’d be sharing a cell with Bernie Madoff or David Ross.

I doubt if he means Peiser as a “so-called scientist”.

And what about whether the poles are melting? It’s not hard to find alternate more scientific views to Dr Benny Peiser and Cameron Slater.

Smithsonian: Ice Melt at the Poles

It’s confirmed: both Antarctica and Greenland are losing ice—around 350 billion tons each year—and, as a result, sea level has risen 11.1 millimeters worldwide since 1992. This photo shows a summertime channel created by the flow of melted ice, which ultimately carries the water away from the glacier to the sea.

It’s not easy to measure melting ice. But by using data from 10 satellite missions, an international team of 47 scientists put together the most accurate estimate of ice melt to date. Ice melt doesn’t just affect sea level, however: the influx of fresh water could change the salinity of the North Atlantic enough to alter weather patterns in North America and affect ocean organisms.

National Snow and Ice Data Center – Artic Sea Ice News and Analysis

Arctic sea ice extent for November was the 9th lowest in the satellite record. Through 2014, the linear rate of decline for November extent over the satellite record is 4.7% per decade.

Antarctic sea ice has continued to decline at a faster-than-average pace (approximately 122,000 square kilometers, or 47,100 square miles per day through the month of October, compared to the average rate of 112,000 square kilometers or 43,200 square miles per day), and is now about 650,000 square kilometers (251,000 square miles) below the level for the date recorded in 2013. Currently ice extent remains about 700,000 square kilometers (270,000 square miles) higher than the 1981 to 2010 average for this time of year.

But what would they know? They aren’t social anthropologists or agenda promoting bloggers.

But an alternate view has been allowed to counter Slater’s claims. See the thread started by Mythrandir.

Another comment, by Gaynor, remains unchallenged:

What would be so wrong with ice free poles? Don’t we need more land for our growing population?

An ice free north pole (Arctic) would not provide more land, there is no land there.

An ice free Greenland would raise sea levels by about 7 metres.

An ice free Antarctic would raise sea levels by about 61 metres.

That would flood a huge amount of land in more habitable parts of the world.

Source: If the polar ice caps melted, how much would the oceans rise?

If the rising temperature affects glaciers and icebergs, could the polar ice caps be in danger of melting and causing the oceans to rise? This could happen, but no one knows when it might happen.

The main ice covered landmass is Antarctica at the South Pole, with about 90 percent of the world’s ice (and 70 percent of its fresh water). Antarctica is covered with ice an average of 2,133 meters (7,000 feet) thick. If all of the Antarctic ice melted, sea levels around the world would rise about 61 meters (200 feet). But the average temperature in Antarctica is -37°C, so the ice there is in no danger of melting. In fact in most parts of the continent it never gets above freezing.

At the other end of the world, the North Pole, the ice is not nearly as thick as at the South Pole. The ice floats on the Arctic Ocean. If it melted sea levels would not be affecte­d.

There is a significant amount of ice covering Greenland, which would add another 7 meters (20 feet) to the oceans if it melted. Because Greenland is closer to the equator than Antarctica, the temperatures there are higher, so the ice is more likely to melt

Of course it’s very unlikely all the world’s ice will melt in the forseeable future. But a metre or two of sea level rise would cause far more problems than it would help.