@NOAA: How tree rings tell time and #climate history

From NOAA (Bruce Bauer):

Most of us learned as children that the age of a tree could be found by counting its rings. Rings of trees growing in temperate climates can indeed tell their age through their annual rings and also help determine the age of wood used to construct buildings or wooden objects. The ages of wooden objects can be revealed by cross-dating, the process of matching ring patterns between wood samples of known and unknown ages.

Concentric rings of various widths mark the annual growth of trees. Photo by Peter Brown, Rocky Mountain Tree-Ring Research. Photo credit: NOAA

What do tree rings tell us

The underlying patterns of wide or narrow rings record the year-to-year fluctuations in the growth of trees. The patterns, therefore, often contain a weather history at the location the tree grew, in addition to its age. In dry environments, such as the Middle East or U.S. Southwest, tree rings typically record wet or dry years, and in cooler areas (high latitudes or high elevation), the ring widths are often a proxy for temperature.

Archeologists have used the ring patterns in building timbers to estimate construction dates for some of the world’s most famous buildings, including the cliff dwellings at Mesa Verde National Park (nearly 1,000 years old) and the Church of the Nativity in Bethlehem (nearly 1,500 years old).

The Cliff Palace ruins at Mesa Verde were built in the 1200s by the Ancestral Pueblo people, but were abandoned in the late part of the century. Photo by Ken Lund, used under a Creative Commons license.

What’s in NOAA’s tree ring data base?

NOAA National Centers for Environmental Information (NCEI) houses the International Tree-Ring Data Bank (ITRDB), which contains ring width data from forests worldwide, plus ring width data from old buildings, and even from rare Stradivari violins. The ITRDB contains ring width data from trees at over 4,600 locations on six continents, providing tree growth histories from around the world. New additions from field scientists are added regularly.

The ring patterns of more than 6,000 trees (green triangles) have been archived in NOAA’s International Tree-Ring Data Bank.

Climate scientists compare the tree growth records to local weather records. For locations where a good statistical match exists between tree growth and temperature or precipitation during the period of overlap, the ring widths can be used to estimate past temperature or precipitation over the lifetime of the tree.

In many parts of the world, trees can provide a climate history for hundreds of years, with some extending back 1,000 years or more. The resulting climate histories enhance our knowledge of natural climate variability and also create a baseline against which human-induced climate change can be evaluated. NCEI archives these climate reconstructions in addition to the tree ring measurements.

Glimpsing the past

Tree ring data have been used to reconstruct drought or temperature in North America and Europe over the past 2,000 years. For example, tree ring based drought reconstructions for the American Southwest indicate a period of prolonged drought in the late 1200’s. Archeologists believe that the drought was a contributing factor in the Ancestral Pueblo People abandoning the famous cliff dwellings at Mesa Verde, never to return.

Severe drought in the U.S. Southwest in the late 1200s likely contributed to the abandonment of Mesa Verde (marked with open circle) by the Ancestral Pueblo people. Drought maps for the years 1275-1290 reconstructed from tree ring records show that over the 16-year span from 1275-1290, only two wet years occurred. Graphic by Climate.gov, based on summer drought reconstructions from the Living Blended Drought Atlas, courtesy of NOAA and Cook et al., 2010, Journal of Quaternary Science, 25(1), 48-61. doi: 10.1002/jqs.1303.

The latest E-Newsletter is hot off the presses from the Hutchins Water Center #ColoradoRiver #COriver #aridification

Changes in the northeastern reaches of Lake Powell are documented in this series of natural-color images taken by the Landsat series of satellites between 1999 and 2017. The Colorado River flows in from the east around Mile Crag Bend and is swallowed by the lake. At the west end of Narrow Canyon, the Dirty Devil River joins the lake from the north. (At normal water levels, both rivers are essentially part of the reservoir.) At the beginning of the series in 1999, water levels in Lake Powell were relatively high, and the water was a clear, dark blue. The sediment-filled Colorado River appeared green-brown. To see the complete series go to: earthobservatory.nasa.gov/WorldOfChange/LakePowell. Photos via NASA

Click here to read the newsletter. Here’s an excerpt:

DROUGHT PLAN SEEMS CLOSER

A Colorado River Drought Contingency Plan to keep water levels in Lakes Mead and Powell from crashing has inched towards completion, as state agencies and key interest groups have endorsed the draft plan over the past month. Endorsing organizations include Nevada water agencies (as reported by the Las-Vegas Review Journal), the Colorado Water Conservation Board and the Colorado River District (despite some reservations, as reported by Aspen Journalism and the Grand Junction Sentinel). Arizona, typically seen as the lone potential hold-out among the states that share the river, has recently made major steps towards an agreement, according to the Arizona Republic. Earlier, the Desert Sun reported that a conflict in a California irrigation district could still complicate adoption of the agreement.

Colorado water agencies going different ways on White River dam project — @AspenJournalism #ColoradoRiver #COriver @CWCB_DNR @DWR_CO

A view of the White River foreground, and the Wolf Creek gulch, across the river. The Rio Blanco Water Conservancy District has been using state funds, and their own, to study two dam options for this area between Meeker and Rangely on the White River. Photo credit: Aspen Journalism/Brent Gardner-Smith

From Aspen Journalism (Brent Gardner-Smith):

The Colorado Water Conservation Board has given $843,338 to the Rio Blanco Water Conservancy District since 2013 to study a potential dam on the White River, yet officials at the Colorado Division of Water Resources say the project appears “speculative” and Rio Blanco lacks evidence for its claims for municipal, irrigation, energy and environmental uses.

On Nov. 14, the CWCB directors approved the most recent grant application from Rio Blanco for $350,000 to keep studying the proposed White River dam and reservoir project near Rangely.

But while the CWCB is spending more state money to help prepare the White River project for federal approval, another state agency, the Division of Water Resources, is asking hard questions about the project in water court.

“There are concerns whether the district can show that it can and will put the requested water rights to beneficial use within a reasonable period of time and that the requested water rights are not speculative,” wrote Erin Light, the division engineer in Division 6, who oversees the White and Yampa river basins, and Tracy Kosloff, the assistant state engineer in Denver, in a report filed in water court Oct. 4.

In addition to pursuing a series of grants from CWCB, Rio Blanco applied in water court in 2014 for a new water right to store 90,000 acre-feet of water from the White River.

The two engineers in the Division of Water Resources filed their report after consulting with the state attorney general’s office. Review of water rights applications by division engineers is routine, but the report filed by the division engineer and assistant state engineer raised a higher level of concerns than normal.

Also known as the Wolf Creek project, it could store anywhere from 44,000 to 2.92 million acre-feet of water, according to the array of proposals, presentations and applications that have been made public over the project’s ongoing evolution. (Please see: Timeline: tracking the proposed White River dam and reservoir).

The water would be stored either in a reservoir formed by a dam across the main stem of the White River, or in an off-channel reservoir at the bottom of the Wolf Creek gulch.

The latest grant from the CWCB to Rio Blanco was to “finalize the preferred reservoir size and firm-up financial commitments of key project partners so that applications for federal permits can be filed,” according to a CWCB staff memo on the grant.

Asked about the apparent conflict between CWCB and DWR on the White River project, CWCB Director Becky Mitchell said she was aware of the concerns voiced by the division and state engineers and was confident that the next phase of study supported by CWCB would help answer some of the questions raised.

“All of the grants given to Rio Blanco thus far have been all about feasibility, so we are not necessarily in disagreement with DWR, but it needs to trued up,” Mitchell said Tuesday. “There may be concerns with what DWR is stating and the grant will help us evaluate those concerns.”

In another sign of CWCB’s support for the potential project, the agency’s finance section has added a potential $100 million loan to Rio Blanco on a list of potential loans it compiles and publishes as part of the CWCB director’s reports to the agency’s directors.

Brad McCloud of EIS Solutions in Grand Junction is serving as Rio Blanco’s project manager for the White River project.

When asked Tuesday about the contradictory messages sent by the two state agencies, McCloud said, “I think one side is working on one end and the other is doing the other and it’s a good check and balance and the way the system is supposed to work. And there are probably things that will get worked out along the way.”

A view looking downstream of the White River in the approximate location of the potential White River dam and reservoir. The right edge of the dam, looking downstream, would be against the brown hillside to the right of the photo. Photo credit: Aspen Journalism/Brent Gardner-Smith

State questions

In their report filed in water court, the state’s water engineers challenge Rio Blanco oft-stated claim it is seeking the new storage facility at Wolf Creek in order to meet the future water needs of the Town of Rangely, which today takes its water directly from the White River.

“While every case is different and may require evidence tailored to the particular facts of the case, the engineers have not received sufficient evidence to support the district’s claimed water demands for Rangely nor evidence that Rangely intends to rely on water storage in one of the Wolf Creek Reservoirs to meet its demand,” the report from Kosloff and Light says.

The engineers’ report also questions the demand for water in the potential new reservoir from the energy sector.

They said Rio Blanco should, at a minimum, show how much of the 45,800 acre-feet of industrial demand it is claiming is located within the district’s boundaries.

They also say Rio Blanco should make public how much of the demand from the energy sector within the district’s boundaries can be satisfied by the existing water rights of the district.

In addition to challenging Rio Blanco’s claims for municipal and industrial use of water in their 2018 report, Light and Kosloff also question Rio Blanco’s claims for irrigation and environmental uses.

They said a storage report prepared for the project “notes that irrigated acreage and irrigation water demand is projected to decrease in the future” in the area downstream of the reservoir.

And the engineers said they “do not believe that a water right for irrigation use should be awarded in this case.”

And the engineers question Rio Blanco claim that it will release up to 42,000 acre-feet of water from its proposed reservoir to the benefit of endangered fish downstream on the White and Green rivers.

They say an ongoing study has yet to make clear how much water is needed for the endangered fish.

“Long story short, it is still unclear what flows should be used when determining if or how much water needs to be stored to assist with meeting the recommended flows,” the report says. “Until these numbers are known, claiming any quantity of water for these uses is speculative.”

Consultants for the Rio Blanco Water Conservancy presenting a slide earlier this year showing how a dam could be built across the main stem of the White River between Rangely and Meeker. A report from engineers at the Division of Water Resources is questioning the claims made in a water court case in which Rio Blanco is seeking new water rights for the project.

Size in flux

The White River project has a wide range of potential uses, according to Rio Blanco, and it also has a wide range of potential sizes, as various presentations and applications have included potential sizes from 44,000 acre-feet to 90,000 acre-feet to 400,000 acre-feet to 2.92 million acre-feet.

Alden Vanden Brink, the manager of the Rio Blanco district, told the CWCB directors Nov. 14 that his district is not seeking to build a 400,000 acre-foot reservoir, despite the reference in Rio Blanco’s grant application to study a reservoir between 44,000 acre-feet and 400,000 acre-feet.

“The 400,000 is maximum size,” Vanden Brink said. “That is not what the Rio Blanco Water Conservancy District is looking to build. It’s going to take somebody from a way outside source to come to the table for that.”

Vanden Brink said the district was seeking to store “anywhere from 44,000 to about 130,000” acre-feet of water.

However, the grant application from Rio Blanco notes that a 400,000 acre-foot reservoir might have some benefit to the state.

“If the higher end of the storage is implemented, the project has tremendous potential to help the majority of the state of Colorado address Colorado River Compact administration issues,” the grant said.

An earlier study on the dam by W.W. Wheeler and Associates for the Rio Blanco district found it was possible to build a dam on the White River at Wolf Creek that would hold 2.92 million acre-feet of water.

The latest grant application to CWCB from the Rio Blanco district says “the preferred reservoir size will be developed based on the amount of water needed and committed to by key project stakeholders.”

Wade Cox, the president of the Rio Blanco Water Conservancy District, discussed the project in October with the board of the Colorado River District, and referenced the varying potential sizes of the reservoir.

“There is never going to be enough water,” Cox said. “I don’t care how big you build it. Whatever you do, it’s never going to be enough. Somebody somewhere is going to utilize it.”

Also, please see related stories:

Economic feasibility of White River off-channel dam and reservoir questioned

Honing in on options for a potential White River Dam near Rangely

Editor’s note: Aspen Journalism covers water and rivers in collaboration with The Aspen Times and other Swift Communications newspapers. The Times published the story on Thursday, Nov. 29, 2018.

@ColoradoClimate: Weekly Climate, Water and Drought Assessment of the Intermountain West

Click here to read the current assessment. Click here to go to the NIDIS website hosted by the Colorado Climate Center.

Gov. Hickenlooper and #Colorado Energy Office award $10.33 million grant to build electric vehicle fast-charging stations across the state #ActOnClimate

Leaf, Berthoud Pass Summit, August 21, 2017.

Heres the release from Governor Hickenlooper’s office:

Governor John Hickenlooper today announced a $10.33 million ALT Fuels Colorado grant through the Colorado Energy Office (CEO) to ChargePoint to build electric vehicle (EV) fast-charging stations along the state’s major transportation corridors. The fast-charging stations will be located in communities at 33 sites across six Colorado corridors comprised of Interstate, State and U.S. highways.

“Fast-charging stations give EV drivers the confidence to reliably travel to all corners of the state,” said Governor John Hickenlooper. “The future of EV travel in Colorado is bright thanks to this new partnership with ChargePoint.”

A lack of EV fast-charging stations along major transportation corridors limits the ability of EV drivers to engage in intra-and interstate travel and represents a major barrier for current and prospective EV owners. The Colorado Electric Vehicle Plan requires the State to build out Colorado’s EV fast-charging infrastructure through public-private partnerships. In April, CEO issued a request for ALT Fuels Colorado grant applications to directly address this requirement. This ALT Fuels Colorado grant also helps implement Colorado’s Beneficiary Mitigation Plan and the State’s commitment to the multi-state Regional Electric Vehicle West Memorandum of Understanding.

“ChargePoint brings technology built for today but capable of serving the next generation of EVs as well, said Colorado Energy Office Executive Director Kathleen Staks. “Charging stations will be placed with well-known site hosts in locations that provide easy access, proximity to amenities and 24/7 charging availability.”

ChargePoint is a national leader in EV charging. The company designs, builds and supports all the technology that powers its charging networks, from charging station hardware to energy management software.

“The transition to electric mobility is upon us, and pioneering states like Colorado are leading the way by supporting a broad charging network that enables long distance electric travel,” said Pasquale Romano, ChargePoint President and CEO. “We share the State of Colorado’s vision of a cleaner, more sustainable electric mobility future, and we look forward to working with the Colorado Energy Office to expand EV charging in the state.”

Woo hoo! DC Fast Charging!

#Drought news: D3 (Extreme Drought) trimmed in Routt County

Click here to go to the US Drought Monitor website. Here’s an excerpt:

Summary

A series of upper-level weather systems, and their associated surface lows and fronts, moved across the contiguous U.S. (CONUS) during this U.S. Drought Monitor (USDM) week. They brought beneficial precipitation to much of the Pacific coast; parts of the northern and central Rockies, central Plains, Midwest, and Gulf of Mexico coast; and much of the Mid-Atlantic to Northeast. But they missed much of the Southwest, northern Plains, and southern Plains, where no precipitation, or less than a tenth of an inch, fell. Based on precipitation recorded through the 12z (7:00 a.m. EST) cutoff on Tuesday morning, the precipitation was less than the weekly normal across parts of the interior Pacific Northwest and northern New England, and much of the Midwest and Southeast. While beneficial, the precipitation in the West was mostly not enough to overcome months of precipitation deficits. Slight contraction of drought or abnormal dryness occurred in parts of Arizona (a reassessment), Colorado, and Montana, while expansion occurred in southern California and Nevada. Building precipitation deficits prompted expansion in the southern Plains. Rain and snow from the weather systems this week – and previous weeks to the last 6 months – have built up precipitation surpluses across much of the country east of the Mississippi River, with streamflow mostly above normal and November 25 reports from the U.S. Department of Agriculture (USDA) showing soil moisture surpluses in most states here, Florida and coastal Georgia and South Carolina being the exceptions. Contraction and expansion of abnormal dryness occurred in coastal Georgia and South Carolina to accommodate a variable precipitation pattern…

West

The Pacific weather systems brought beneficial rain and snow to coastal Washington and Oregon, and parts of central to northern California and the Sierra Nevada range. Widespread amounts of 2-4 inches occurred, with locally up to 5 inches in parts of northern coastal California and the Sierra, and 5-10 inches in the Olympic Peninsula of western Washington. Some parts of the Sierra Nevada measured more than a foot of new snow. The rain helped firefighters contain the Camp wildfire and snow improved mountain snowpack. But it wasn’t enough to overcome precipitation deficits which have built up over many months. While the week was wetter than normal in California, coastal Washington, and parts of Oregon, the water year to date (October 1-November 27), and even month to date (November 1-27), were still drier than normal in most areas. The precipitation was enough to prevent further expansion of drought areas, but not enough for improvement this week. Little to no precipitation fell further south. In southern California and southern Nevada, D1 expanded across parts of Nye, Esmeralda, and Inyo Counties where dryness this week and the last several weeks, as well as long-term dryness, were reflected in the SPI, SPEI, soil moisture models, and groundwater indices.

Half an inch to locally over 2 inches of precipitation fell across parts of the northern to central Rockies as the weather systems moved past, improving the snowpack half a foot to a foot in many places. In Colorado, D3 was trimmed in Routt County where recent precipitation has dropped SPIs and snowpack has improved. But further south, except for the northern Utah and Colorado mountains, little to no precipitation occurred across the Four Corners States. Some improvement occurred in southwest Arizona as a re-assessment of conditions. D1 was trimmed in Maricopa to Yuma Counties, and D2 reduced in La Paz County, where the heaviest rains fell over the last 2 months. The SPI shows wet conditions across much of Arizona, especially the southern portions, for the last 2 to 9 months and even 24 months. However, how and when the precipitation fell is very important. A lot of the rain fell in only a couple heavy rain events in the first 2 weeks of October. Much of the rain probably just ran off and didn’t get a chance to really contribute to the total moisture status, but it shows up in the SPI as wet. Also, the hot temperatures of recent months and years have enhanced evapotranspiration (ET), and this is reflected in very dry SPEI values, especially at time scales of 6 months and longer. The drought depiction in Arizona reflects these longer-term drought conditions…

High Plains

Half an inch to an inch of precipitation fell in areas across Wyoming, Nebraska, and northern Kansas, with little to no precipitation occurring in the Dakotas and the High Plains of Montana. The precipitation was not enough to affect the D0-D1 lingering in northeast Kansas. Even though the week was drier than normal in north central Montana, the D0 there was trimmed to reflect a reassessment of the impact of precipitation in recent weeks. The D0-D1 in the Dakotas reflected lingering long-term dryness…

South

Half an inch of precipitation fell across parts of coastal Texas and Louisiana, parts of Mississippi, and extreme northeastern Arkansas. But most of Texas and Oklahoma received no precipitation this week, and have been drier than normal for most of the last 4-7 weeks. Mounting dryness over the last 3-6 months prompted expansion of D0-D1 in northeast Oklahoma into northwest Arkansas, with some D0 expanding into adjacent southwest Missouri and bleeding slightly into adjacent southeast Kansas. The areas of D0-D1 in Texas remained unchanged this week…

Looking Ahead

A Pacific weather system was moving across the West during Tuesday and Wednesday after the 12z cutoff time of the USDM, bringing more beneficial rain and snow to the drought areas of the Pacific coast to Great Basin; another was poised to move into the West Coast by the release time of this USDM report; a third is expected to bring more precipitation to the West over the weekend; while a fourth Pacific front is forecast to reach the coast by Tuesday morning. These weather systems will cross the Rockies and re-energize when they reach the Plains, picking up Gulf of Mexico moisture to bring precipitation to the central and eastern portions of the CONUS. The NWS Quantitative Precipitation Forecast (QPF) for November 28-December 4 calls for 3-6 inches of new precipitation across the Sierra Nevada to northern California, and in spotty areas of coastal Oregon and Washington, with 2+ inches in parts of the Midwest, in a couple strips across the Southeast, speckled across the Four Corners States, and in parts of southwest Alaska. Half an inch to 2 inches of precipitation is predicted for the Great Basin to central and southern Rockies, much of the Midwest, and parts of the Northeast. Outside these areas, 0.25 to 0.50 inch is expected to fall, except little to no precipitation is forecast for southern portions of the Southwest, much of Texas and Oklahoma, much of the northern Plains, and eastern Alaska. Above-normal temperatures will precede the fronts, especially in the eastern CONUS, with below-normal temperatures following them, spreading across most of the CONUS by the end of the period. The outlook for December 4-12 has colder-than-normal temperatures dominating the CONUS with warmer-than-normal temperatures across Alaska as a classic ridge/trough upper-level weather pattern sets up. Late in the period, warmer-than-normal air moves into the West as the trough migrates further east. Odds favor below-normal precipitation along the northern tier states and Alaska panhandle, and above-normal precipitation along the southern tier states, across much of the West, and the rest of Alaska.

#ClimateChange signals and impacts continue in 2018 — World Meteorological Organization #ActOnClimate

Here’s the release from the World Meteorological Organization:

The long-term warming trend has continued in 2018, with the average global temperature set to be the fourth highest on record. The 20 warmest years on record have been in the past 22 years, with the top four in the past four years, according to the World Meteorological Organization (WMO).

Other tell-tale signs of climate change, including sea level rise, ocean heat and acidification and sea-ice and glacier melt continue, whilst extreme weather left a trail of devastation on all continents, according to the WMO provisional Statement on the State of the Climate in 2018. It includes details of impacts of climate change based on contributions from a wide range of United Nations partners.

The report shows that the global average temperature for the first ten months of the year was nearly 1°C above the pre-industrial baseline (1850-1900). This is based on five independently maintained global temperature data sets.

“We are not on track to meet climate change targets and rein in temperature increases,” said WMO Secretary-General Petteri Taalas. “Greenhouse gas concentrations are once again at record levels and if the current trend continues we may see temperature increases 3-5°C by the end of the century. If we exploit all known fossil fuel resources, the temperature rise will be considerably higher,” he said.

“It is worth repeating once again that we are the first generation to fully understand climate change and the last generation to be able to do something about it,” said Mr Taalas.

The Intergovernmental Panel on Climate Change (IPCC) special report on Global Warming of 1.5°C reported that the average global temperature for the decade 2006-2015 was 0.86°C above the pre-industrial baseline. The average increase above the same baseline for the most recent decade 2009-2018 was about 0.93°C and for the past five years, 2014-2018, was 1.04°C above the pre-industrial baseline.

“These are more than just numbers,” said WMO Deputy Secretary-General Elena Manaenkova.

“Every fraction of a degree of warming makes a difference to human health and access to food and fresh water, to the extinction of animals and plants, to the survival of coral reefs and marine life. It makes a difference to economic productivity, food security, and to the resilience of our infrastructure and cities. It makes a difference to the speed of glacier melt and water supplies, and the future of low-lying islands and coastal communities. Every extra bit matters,” said Ms Manaenkova.

The WMO report adds to the authoritative scientific evidence that will inform UN climate change negotiations from 2-14 December in Katowice, Poland. The key objective of the meeting is to adopt the implementation guidelines of the Paris Agreement on Climate Change, which aims to hold the global average temperature increase to as close as possible to 1.5°C.

The IPCC report on Global Warming of 1.5°C said that this target was physically possible but would require unprecedented changes in our lifestyle, energy and transport systems. It showed how keeping temperature increases below 2°C would reduce the risks to human well-being, ecosystems and sustainable development.

National meteorological and hydrological services have been contributing to national climate assessments. A new U.S. federal report detailed how climate change is affecting the environment, agriculture, energy, land and water resources, transportation, and human health and welfare, with a risk that it will lead to growing losses to American infrastructure and property and impede the rate of economic growth over this century.

A UK assessment published 26 November warned summer temperatures could be up to 5.4°C hotter and summer rainfall could decrease by up to 47% by 2070, and sea levels in London could rise by 1.15m by 2100. A Swiss report on climate scenarios released on 13 November said that Switzerland is becoming hotter and drier, but will also struggle with heavier rainfall in the future and its famed ski resorts will have less snow.

“The WMO community is enhancing the translation of science into services. This will support countries in generating national climate scenarios and predictions and developing tailored climate services to reduce risks associated with climate change and increasingly extreme weather. WMO is also working to develop integrated tools to monitor and manage greenhouse gas emissions and carbon sinks,” said WMO Chief Scientist and Research Director Pavel Kabat.

Highlights of the provisional statement on the state of the climate

Temperatures: 2018 started with a weak La Niña event, which continued until March. By October, however, sea-surface temperatures in the eastern Tropical Pacific were showing signs of a return to El Niño conditions, although the atmosphere as yet shows little response. If El Niño develops, 2019 is likely to be warmer than 2018.

Greenhouse gases: In 2017, carbon dioxide, methane and nitrous oxide concentrations reached new highs, according to WMO Greenhouse Gas Bulletin. Data from a number of locations, including Mauna Loa (Hawaii) and Cape Grim (Tasmania) indicate that they continued to increase in 2018.

Oceans: The oceans absorb more than 90% of the energy trapped by greenhouse gases and 25% of anthropogenic CO2 emissions, making them warmer and more acidic. For each 3-month period until September 2018, ocean heat content was the highest or second highest on record. Global Mean Sea Level from January to July 2018 was around 2 to 3 mm higher than the same period in 2017.

Sea ice: Arctic sea-ice extent was well below average throughout 2018 with record-low levels in the first two months of the year. The annual maximum occurred in mid-March and was the third lowest on record. The minimum extent in September was the 6th smallest on record, meaning that all 12 smallest September extents have been in the past 12 years. Antarctic sea-ice extent was also well below average throughout 2018. The annual minimum extent occurred in late February and was ranked as one of the two lowest extents.

Extreme Weather

Tropical Storms: The number of tropical cyclones was above average in all four Northern Hemisphere basins, with 70 reported by 20 November, compared to the long-term average of 53, leading to many casualties. The Northeast Pacific basin was especially active, with an Accumulated Cyclone Energy that was the highest since reliable satellite records began.

Two of the strongest tropical cyclones were Mangkhut, which impacted the Philippines, Hong Kong SAR and China, and Yutu, which brought devastation in the Mariana Islands. Jebi was the strongest typhoon to hit Japan since 1993, Son-Tinh caused flooding in Viet Nam and Laos, whilst Soulik contributed to flooding on the Korean peninsula. Hurricanes Florence and Michael were associated with huge economic damage and considerable loss of life in the United States. Gita, in the South Pacific, was the most intense and most expensive cyclone to ever hit Tonga.

Floods and rainfall: In August, the southwest Indian state of Kerala suffered the worst flooding since the 1920s, displacing more than 1.4 million people from their homes and affecting more than 5.4 million. Large parts of western Japan experienced destructive flooding in late June and early July, killing at least 230 people and destroying thousands of homes. Flooding affected many parts of east Africa in March and April. This included Kenya and Somalia, which had previously been suffering from severe drought, as well as Ethiopia and northern and central Tanzania. An intense low-pressure system in the Mediterranean Sea in late October brought flooding, high winds and loss of life.

Heatwaves and drought: Large parts of Europe experienced exceptional heat and drought through the late spring and summer of 2018, leading to wildfires in Scandinavia. In July and August, there were numerous record high temperatures north of the Arctic Circle, and record long runs of warm temperatures., including 25 consecutive days above 25 °C in Helsinki (Finland). Parts of Germany had a long spell of days above 30°C, whilst a heatwave in France was associated with a number of deaths. It was also an exceptionally warm and dry period in the United Kingdom and Ireland. A short but intense heatwave affected Spain and Portugal in early August.

Dry conditions were especially persistent in Germany, the Czech Republic, western Poland, the Netherlands, Belgium and parts of France. The Rhine approached record low flows by mid-October, seriously disrupting river transport.

Eastern Australia experienced significant drought during 2018, especially New South Wales and southern Queensland, with much of the region receiving less than half its average rainfall for the period from January to September. Severe drought affected Uruguay, and northern and central Argentina, in late 2017 and early 2018, leading to heavy agricultural losses.

Both Japan and the Republic of Korea saw new national heat records (41.1 °C and 41.0°C respectively.)

Oman reported one of the highest known minimum overnight temperature of 42.6 °C in June. Algeria saw a new national of 51.3 °C in July.

Cold and snow: One of the most significant cold outbreaks of recent years affected Europe in late February and early March.

Wildfires: Major wildfires affected Athens (Greece) on 23 July, with many fatalities. British Columbia in Canada broke its record for the most area burned in a fire season for the second successive year. California suffered devastating wildfires, with November’s Camp Fire being the deadliest fire in over a century for the U.S.A.

Other Impacts

The provisional statement contained details of impacts of climate change, based on contributions from the Food and Agriculture Organization (FAO), International Organization for Migration (IOM), UN Environment Programme (UNEP), UNESCO’s Intergovernmental Oceanographic Commission (IOC), UN High Commission for Refugees UNHCR) and World Food Programme (WFP). This section will be expanded in the final statement, to be released in March 2019.

Exposure of agriculture sectors to climate extremes is threatening to reverse gains made in ending malnutrition. New evidence shows a rise in world hunger after a prolonged decline. In 2017, the number of undernourished people was estimated to have increased to 821 million, according The State of Food Security and Nutrition in the World 2018, by to FAO, WFP, the International Fund for Agricultural Development, the UN Children’s Fund and the World Health Organization. Africa is the region where climate events had the biggest impact on acute food insecurity and malnutrition in 2017, affecting 59 million people in 24 countries and requiring urgent humanitarian action. Much of the vulnerability to climate variability is associated with the dryland farming and pastoral rangeland systems supporting 70–80% of the continent’s rural population.

Out of the 17.7 million Internally Displaced Persons tracked by the IOM, 2.3 million people were displaced due to disasters linked to weather and climate events as of September 2018. In Somalia, some 642 000 new internal displacements were recorded between January and July 2018 by UNHCR, with flooding the primary reason for displacement (43%), followed by drought (29%), and conflict (26%).

UN agencies including UNESCO-IOC and UNEP are tracking environmental impacts associated with climate change include coral bleaching, reduced levels of oxygen in the oceans, loss of “Blue Carbon” associated with coastal ecosystems such as mangroves and salt marshes. Climate change also exposes peatlands currently protected by permafrost to thawing and possible increased methane emissions and loss of carbon, and the associated sea-level rise increases the risks of coastal erosion and salination of freshwater peatlands.