Your one-stop source for sea-level information, with interactive tools for linear and quadratic regression analysis, and graphing, of measured sea-level trends, at over 1200 locations.

Learn about climate change...

The benefits of higher CO2 levels for crops have been known for a century; this photo contrasting large potatoes grown with extra CO2 to small potatoes grown without it from a 1920 Scientific American article.

If you'd like to learn more about climate change, here are some trustworthy resources:
https://tinyurl.com/learnmore4

News...

November 23, 2024 — NEW! I consider myself a “climate skeptic,” because I dispute the alarmist narrative about climate change. The best evidence is that manmade climate change is modest and benign, and CO₂ emissions are beneficial rather than harmful, both for humanity, and for natural ecosystems.
However, that doesn't mean I agree with everyone else who calls themself a climate skeptic. Some criticisms of the climate scare are wrong.
Here are two critiques I've written of irredeemably flawed papers by self-styled skeptics. In both cases, the papers were printed in “pay-to-publish” open access journals, which initially agreed to publish my comments, but which subsequently declined to do so:
1. Comment on Stallinga (2023), Residence Time vs. Adjustment Time of Carbon Dioxide in the Atmosphere. doi:10.31219/osf.io/brdq9.
2. Letter: Errors in Lightfoot & Ratzer (2024), Reliable Physics Demand Revision of the IPCC Global Warming Potentials. doi:10.5281/zenodo.14242045.
March 22, 2024 — I have links to download Climate, The Movie, or to watch it online, here.
I had nothing to do with creating this documentary, but I highly recommended it. In the entire movie I heard only 3 or 4 sentences that I disagreed with. The main one was a suggestion by someone (I've forgotten who) that there could be some doubt about whether raising the CO2 level has any warming effect at all. In fact, there is no argument about that. The warming effect of additional CO2 is modest and benign, but it is not zero. Other than that tiny nit, I unreservedly recommend this documentary.
March 14, 2024 — Another WUWT article: The AI Buzz
March 31, 2023 — Another WUWT article: More Nonsense About Greenland
February 24, 2022 — The “P.S.” menu item now works. ↑
February 22, 2022 — I've added information about forest fires to the https://sealevel.info/learnmore.html (“Learn More About Climate Change”) page, and made some structural improvements to the web site.
Many of the topics on the https://sealevel.info/learnmore.html page now have customized-per-topic Twitter and Facebook “cards” defined. So, for example, if you Tweet a link to https://sealevel.info/learnmore.html?0=fires#fires the tweet will look something like this:

But if you Tweet a link to https://sealevel.info/learnmore.html?0=sealevel#sealevel the tweet will look like this:

The top-of-page menus have also been restructured. ↑
November 29, 2021 — I've created a little online spreadsheet, where you can enter your own estimates for common climate parameters, like the percentage of warming since the LIA which was caused by man, the ECS-to-TCR ratio, etc., and it will calculate estimates of climate sensitivity, unrealized warming “in the pipe,” and Earth's radiative imbalance:
https://sealevel.info/radiative_imbalance_calc.htm
It also includes notes and references for how those things can be estimated and calculated. ↑
April 3, 2021 — I've built an extreme-precision binomial probability calculator, in Perl. (On Windows I use Strawberry Perl, but most recent version 5 Perls should work.) To download it, right-click here, and "save link as" or "save target as," or similar. It is a work in progress; no warranties, express nor implied.
April 12, 2021 — I've added a web interface to the extreme-precision binomial probability calculator.
April 23, 2020 — I've greatly improved the extreme-precision binomial probability calculator, especially the performance.
May 24, 2021 — I've enhanced the extreme-precision binomial probability calculator, to try to display only the correct number of significant digits in results. ↑
March 25, 2021 — I've consolidated my collection of information about Covid-19, vaccines, and investigational treatments, here: https://sealevel.info/covid.html ↑
February 11, 2021 — Have you marveled at the depth of division in today's society? My friend, Payne Kilbourn, explains how it happened. ↑
December 23, 2020 — Here are the references (and other Covid-19-related resources) for my Washington Times guest op-ed, Sunday Dec. 27 online, Monday Dec. 28 in print (archived here). ↑
September 2, 2020 — My guest column on WND: Dr. Scott Atlas is dead wrong about handling COVID (or pdf, or preprint). ↑
August 8, 2020 — Much of reddit is very heavily censored, to enforce uniformity of leftist thought. They “shadowban” users' comments, to try to prevent the users from realizing that they're censored. This is a shadowbanned comment which I attempted to post, in reply to someone who is worried about “ocean acidification.” If ocean acidification worries you then you might find my remarks encouraging. ↑
June 29, 2020 — This is an extraordinary mea culpa from uber-environmentalist Michael Shellenberger: On behalf of environmentalists, I apologize for the climate scare (or pdf). ↑
June 20, 2020 — I am very grateful to the kind folks at the Polish Institute of Meteorology and Water Management, who sent me the latest sea-level measurements for Swinoujscie, Poland. It now has data from January, 1811 through December, 2019, with just one six-year gap, plus one seven-month gap, making it indisputably one of the very best long sea-level measurement records in existence. ↑
June 12, 2020 — A few people claim that atmospheric CO₂ levels are rising, not because of mankind's CO₂ emissions, but, rather, because the oceans are outgassing CO₂, due to global warming. They're wrong. ↑
May 31, 2020 (updated June 25, 2020) — This site now has tools to graph and analyze sea-level measurements from weighted averages of lists of tide gauge locations, instead of just one site at a time. So you can create your own “sea-level index” using the data you trust the most.
Currently, it just omits months for which one or more sites lack data, except that it will interpolate for single missing months.
Here's an example (Honolulu+Harlingen). Click the image to see the source page and latest data: ↑
May 16, 2020 — We've updated the sea-level data with the latest from NOAA. If you notice any problems, please tell Dave, ASAP!
May 6, 2020 — We've updated the sea-level data with the latest from PSMSL ("27 Apr 2020"). If you notice any problems, please tell Dave, ASAP! ↑
May 3, 2020 — Sealevel.info is on a new server today. If you notice any problems, please tell Dave, ASAP!
~~The old server can temporarily still be accessed at http://sealevel.info:8080/.~~ ↑
April 21, 2020 — The Scientific Case for Vacating the EPA's Carbon Dioxide Endangerment Finding, by Patrick J. Michaels. ↑
April 20, 2020 — “Expert” estimates of the true number of cases of COVID-19 in the United States vary by more than a factor of ten. However, we can work backward from the number of fatalities, and the best-case (South Korean!) fatality rate, to estimate the true number of cases.
When we do that arithmetic, we find that for every known COVID-19 case in the U.S. there have probably been between 1.1 and 4.6 undetected cases (2.85 ±1.75), which were (or are so far) either completely asymptomatic, or had (or have) symptoms too mild to require hospitalization.
Based on the current number of known U.S. cases (764,265), that indicates that the actual number of COVID-19 cases in the U.S. is between 1.6 & 4.3 million (i.e., 3.0 ±1.4 million), which is 0.9±0.4 percent of the U.S. population. ↑
April 17, 2020 — To calculate the true COVID-19 fatality rate for a country like the United States, were many cases are undiagnosed, and where many of the infections have not run their course (so we don't know how many will recover, and how many will die), is challenging, and estimates vary widely.
But the calculation is not challenging for South Korea. They've used aggressive testing and contact tracing to identify nearly everyone who is infected, regardless of whether they have symptoms. Plus, 70% of their cases are resolved, and they've nearly eradicated the disease. So they have “near-final” data.
From that data we can calculate that the true CV-19 fatality rate in South Korea is between 2.16% and 2.87%. (That's with very early diagnosis and treatment, and an unstressed healthcare system; in most other countries the fatality rate is undoubtedly worse.) ↑
April 10, 2020 — WUWT article: AR6 WG1 SOD Reviewers are needed — please light a candle
March 12, 2020 — The Heartland Institute has created a new and very useful web site called, “Climate At A Glance.” It currently has twenty brief, but high-quality, articles on climate-related topics. ↑
January 22, 2020 — The highest quality surface temperature measurements in the world are from the U.S. Climate Reference Network (USCRN). Unfortunately, the USCRN data only goes back to 2005. But it shows that in the “lower 48” States there's been no clear temperature trend over the last fifteen years.
In the contiguous United States, 2019 was the 11th warmest year, and the 5th coolest year, of the last 15 years. Here's a spreadsheet with the data, here's NOAA's graph, and here's a good article about it. ↑
January 7, 2020 — Tomorrow's edition of The Pilot newspaper will include my guest op-ed column about Prof. Mann's misleading Dec. 5, 2019 presentation in Southern Pines. Here's a copy of the article with hyperlinked references added: https://sealevel.info/thepilot ↑
December 6, 2019 — Prof. Michael Mann was in North Carolina last night, to deliver a Ruth Pawley Lecture in Southern Pines. I attended. These are my notes.
August 31, 2019 — CNN vs. what the science says (and there's a slightly abbreviated version on WUWT).
August 27, 2019 — Former President Obama apparently doesn't actually believe the nonsense he used to parrot, about dangerous climate change and sea-level rise. He and Michelle just purchased an enormous seaside mansion, barely above sea-level, on Martha's Vineyard.
January 31, 2019 — Drs. Roy Spencer and John Christy debunk speculation that global warming causes frigid winters: If the Polar Vortex is due to Global Warming, Why are U.S. Cold Waves Decreasing? ↑
December 19, 2018 — Dave Burton's remarks to Gov. Cooper's “NC Climate Change Interagency Council” (which apparently fell on deaf ears). ↑
December 8, 2018 — I can recommend this excellent guest editorial today by Paul Driessen, at TownHall.com: Climate Lunacy Takes Center Stage ↑
November 14, 2018 — Most readers here probably know that I am very honored to have been invited to join the CO2 Coalition, an organization of mostly-prominent scientists (plus a few no-names like me!), dedicated to de-politicizing the public debate surrounding CO₂ emissions and climate change, and helping to substitute sound scientific analysis for unscientific climate hysteria.
Today I'm pleased to share a letter by Prof. William H. Smith (pdf or ePub), entitled, The Double Bind and Scientific Honesty, in which (among other things) he explains why he, too, is very pleased to be a member of the CO2 Coalition.
In his letter Prof. Smith also mentions this 30 year old (1988) editorial, by the late Dr. Stephen Schneider, in which Dr. Schneider wrestled with “groping to find the balance between being effective and being honest.” Not mentioned in his editorial was the fact that, at that time, Dr. Schneider was a relatively fresh convert to global warming alarmism. A decade earlier, he made an appearance in this 1978 television program (starting at about the 6:00 minute mark), worrying about (can you guess?), global cooling. ↑
October 7, 2018 — An audit of global warming data finds it riddled with errors: #Datagate! First ever audit of global temperature data finds freezing tropical islands, boiling towns, boats on land.
Follow-up (Oct. 15) — Met Office responds to HadCRUT global temperature audit by McLean. ↑
September 26, 2018 — I can highly recommend this excellent article by Jim Steele on WUWT, about the tug-of-war in California between science and sea-level alarmism. ↑
September 24, 2018 — Another short WUWT article:
Greenland Ice Sheet apparently gains mass for the 2nd year in a row. ↑
September 10, 2018 — ~~Apologies in advance if sealevel.info goes down during the hurricane, which is likely.~~ In the meantime, if you want to learn more about climate change, here are some good resources:
https://sealevel.info/learnmore.html
UPDATE: Thankfully, we had no problems, and no damage. The power didn't even go off. ↑
August 15, 2018 — Our CO₂ data and graphs have been updated to include an estimate for 2018, 408.4 ppmv (based on seasonally-adjusted June & July measurements). ↑
August 14, 2018 — WUWT article: A shining example of @Google and @YouTube protecting us against misinformation. ↑
August 13, 2018 — I'm looking forward to watching this series of educational lectures, from Camp Constitution 2018:
1. Climate Change, with Lord Monckton
2. California Wild Fires, Agenda 21-2030, with Debbie Bacigalupi
3. The Global Warming, Climate Change Hoax, with Prof. Willie Soon
4. Are the Sea Levels Rising? with Prof. Willie Soon ↑
July 2, 2018 — Prof. Ross McKitrick's June 20, 2018 Financial Post article is an exceptionally clear yet thorough discussion of ECS climate sensitivity. (You can also find information on that topic on the salevel.info “Resources” page.) ↑
June 2, 2018 — We got a letter to the editor in the Wall Street Journal, with a lot of help from my friends, meteorologist Tom Wysmuller, and Prof. Will Happer. Here's the original version, as we submitted it (with references and a graph).
Here's the WSJ's online version (or here):
https://www.wsj.com/articles/you-wouldnt-think-sea-level-is-so-complex-1527873471

(click to enlarge) ↑
Our letter was in response to one by Profs. Andrea Dutton and Michael Mann. For a critique of a video interview with Prof. Dutton, see:
https://sealevel.info/zapatka-dutton_cmts01.html
If you want to learn more about climate change, here are some good resources:
https://sealevel.info/learnmore.html
Our sites:
https://sealevel.info (Burton)
http://colderside.com (Wysmuller)
https://co2coalition.org (Happer, et al)
The top climate blog (news & discussion):
http://wattsupwiththat.com
April 26, 2018 — Updated with latest PSMSL data.
April 14, 2018 — It's now been six years since the “Fakegate” scandal, in which the Climate Movement's top ethicist, Dr. Peter Gleick, and the climate activists at DeSmogBlog, conspired to smear Heartland Institute with a clumsily forged fake “strategy memo.”
They got caught, which you'd think would end their careers, and land at least some of them in prison. But it really hasn't hurt them much. The Obama-appointed U.S. Attorney protected them by refusing to prosecute until the statute of limitations had run out, and most climate activists don't seem to mind being lied to.
March 27, 2017 — A Tutorial On Climate Change. Oakland and San Francisco, California, have have filed lawsuits against oil companies to recover costs associated with adapting to climate change. U.S. District Judge William Alsup, who is presiding over the case, requested that the parties provide tutorials on climate change and the history of climate science.
This is one such tutorial, submitted to the Court as an amicus brief by three extremely distinguished scholars: Drs. William Happer, Steven Koonin, and Richard Lindzen: Happer-Koonin-Lindzen.pdf (or here)
February 14, 2018 — A few decades ago, the focus of most “climate scientists” (who were generally called climatologists, back then), shifted from observations to modeling. These days, all the climate catastrophists' predictions are based on alarming computer models, which, despite 2/3 century of rapidly climbing greenhouse gas emissions and levels, are still largely unconfirmed by measurements.
Enough time has elapsed to compare those early computer projections with measured reality. So how have they fared? Here I examine the very alarming predictions of a groundbreaking and highly influential 1988 climate modeling paper:
http://sealevel.info/hansen1988_retrospective.html
3½ months after that paper was published, the IPCC was founded, to address that perceived problem—which turns out to have been much ado about very little.
January 19, 2018 — I am quite impressed by PragerU's videos on climate change.
October 27, 2017 — How did news organizations like WRAL come to believe that it's valid journalism to seek out "experts" at only one extreme of the range of the scientific opinion, for their "documentaries?" That's not news reporting, that's propagandizing.
Here's NC's longest, highest-quality sea-level record (Wilmington), plus the WRAL prediction.

Sea-level there has been rising at about 2.3 mm/year for the last 82 years. WRAL predicts 11.1 mm/year over the next 83 years = ~5x as fast as the real trend. That's despite the fact that, other than spikes with strong El Ninos, there's been no significant acceleration in sea-level rise, so far.
Read more here:
http://sealevel.info/cmt_on_wral_2017-10_sealevel_documentary.html
October 25, 2017 — The New Republic and Wired both ran a ridiculous disinformation story entitled, “Climate Change Is Killing Us Right Now.” This was my reply:
http://sealevel.info/Emily_Atkin_Climate_Change_Is_Killing_Us_Now_is_nonsense.html
On Tuesday, Sept. 12, 2017, at 7 p.m. there ~~will be~~ was an ICON Lecture in Chapel Hill, NC, with my friend, Princeton physicist Will Happer. (I manned the info table.)
http://sealevel.info/Happer_ICON_lecture_2017.html
July 29, 2017 — Our Internet service went down yesterday, and it's still down. As of this morning, the server is back up (sort of), limping along on a lower-bandwidth, jury-rigged temporary connection. Please forgive the outage and the sluggish response times.
Update: as of July 31, 2017 we're back up on the regular connection.
June 1, 2017 — I'm proud that North Carolina's U.S. Senator Thom Tillis signed this excellent letter to President Trump:
http://sealevel.info/Letter_from_22_US_Senators_to_President_Trump_on_Paris_climate_treaty.pdf
May 23, 2017 — I've made several minor improvements on the site. One is that on the data analysis pages for tide gauges you may now override the default width and height for the graphs.
May 21, 2017 — New WUWT article: Climate scientist Josh Willis shows you how to deal with your climate change denying uncle - but fails.
March 27, 2017 — I've added an option to plot an extra line segment or curve, typically used to display a forecast of future sea-level rise. The projection can be drawn with either a constant acceleration curve, or a constant slope (linear). For example, here are the linear and constant acceleration graphs showing the wildly unrealistic accelerations required to reach the “three feet by 2060” prediction of some of the crazier climate alarmists for Miami.
February 9, 2017 — The Next / Previous buttons on the sea-level analysis pages now do a better job of taking you to a related page (e.g., another site in the same country/coast).
January 26, 2017 — Try the new (preliminary) country/coastline code list on the Data page.
January 21, 2017 — Article on WUWT about this site: New website gives you the real deal on sea level rise and rates (or here).
January 9, 2017 — All 1269 tide stations now have "thumbnail" graphs. (Technical note: the graphs are generated using Google Visualization tools, in Javascript — which can't write files. Ask me how I extracted the graphs, to make the thumbnail files!)
January 5, 2017 — First release of interactive sea-level analysis and visualization tools. There are currently 1269 tide-station locations in the database, with sea-level data.
There are still a few rough edges, and a hefty to-do list; your feedback is valued!
December 25, 2016 — Merry Christmas! For your holiday enjoyment, here are five facts about climate change, which I posted on Quora.
Here's an earlier Quora screed, about what it means to be a “skeptic” about global warming.
December 2, 2016 — North Carolina's top environmental official, DEQ Secretary Don van der Vaart, has written two excellent letters about the role and policies of the EPA, which are worth your time to read. The first, which was also signed by the top environmental officials of four other States, was to President-elect Donald Trump. The second was to EPA Administrator Gina McCarthy. ↑
October 3 - November 27, 2016 — Here's a preview of upcoming sea-level visualization tools at SeaLevel.info. These are graphs of sea-level at Honolulu, Hawaii, Wilmington, North Carolina, Chuuk Atoll, Micronesia, Brest, France and many other locations, with many interactive features and options.

Options are provided to choose the data source (NOAA vs. PSMSL, though not yet for all locations), to choose whether to display the linear trend (calculated from all available data, rather than recalculated every few years, as NOAA does) and/or quadratic trend (for detecting acceleration/deceleration), and to choose whether to display confidence intervals, prediction intervals, and CO2 level. Additionally, you can optionally constrain the range of dates shown or analyzed, smooth the data in various ways, and adjust various display options, such as colors and line thickness.
April 6, 2016 — Sea-level is not rising everywhere. The measured rate of coastal sea-level change varies from -17.59 mm/yr at Skagway, Alaska to +9.39 mm/yr at Kushiro, Japan. The average, as measured by the world's best long-term coastal tide gauges, is just under +1.5 mm/yr. That rate has not increased (“accelerated”) in over 85 years.
March 28, 2016 - Ooops! Alarm over sinking islands premature as sea level falls at Kwajalein Atoll.
February 3, 2016 — New "Feedbacks" page added. Everything You Always Wanted to Know About Climate Feedbacks* (*But Were Afraid to Ask).
It's still a bit rough around the edges. As always, I would be grateful for your ~~feedback~~ comments & corrections.
December 18, 2015 — The Heartland Institute is one of the world's finest public policy think tanks, and they've compiled an impressive collection of information about the COP-21 Paris climate conference, here: https://www.heartland.org/Cop21/
P.S. (12/28/2015) — someone complained about this link, who had apparently been misled by the Peter Gleick / DeSmogBlog forged document smear of Heartland. If you're not familiar with the story, read on. Dr. Gleick tried to anonymously distribute a “strategy memo” purportedly leaked from Heartland, which was actually a forgery, almost certainly created by Gleick, himself. Here's an article about the affair, from The Atlantic. Gleick was subsequently rewarded for his crimes by National Geographic's ScienceBlog subsidiary, where he's now their resident “scientist, innovator, and communicator” on global water, environment, climate, and presumably identity theft, fraud, character assassination, and forgery. ↑
December 14, 2015 — Good essay today in USA Today by Rep. Lamar Smith (R-TX), chairman of the U.S. House Science, Space and Technology Committee.
December 8, 2015 — The Resources page of this site got a long-overdue reorganization. Suggestions for further improvement are very welcome.
October 16, 2015 — Environmentalist David Siegel shares What I Learned about Climate Change. He learned a lot, and so can you.
May 12, 2015 — Australia's Joanne Nova reports on The scandal of sea levels — rising trends, acceleration — largely created by adjustments.
May 5, 2015 — Here are Dave Burton's remarks at the North Carolina Coastal Resources Commission meeting in Manteo, NC, on April 29, 2015. It's part of the latest chapter in North Carolina's simmering kerfuffle over sea-level rise.
April 2, 2013 — NOAA has released a major update of their tidestation data, with updated trend analysis and graphs for many stations, and many newly-analyzed PSMSL stations! See the new 2013 spreadsheets on the sealevel.info data page. (Note: as a result of these changes there are a few dead links in some of the older spreadsheets, which I've not yet fixed.)
March 23, 2013 — Rev 0.7, added a spreadsheet with just the 45 NOAA-administered GLOSS-LTT tide stations, and also one with just the 42 of those 45 for which there was data through 2011. (The other stations were three Pacific Islands: Johnston Atoll, Pago Pago, and Chuuk.)
Notes: In 2012 NOAA recalculated sea-level trends for those 42 U.S. tide gauges using data through 2011. The results were illuminating.

The sea-level records for the 42 gauges had an average duration of 87.4 years (through 2011), and NOAA's calculated trends had an average confidence interval of ±0.515 mm/yr.

When new (through 2011) trends were compared to the old (through 2006) trends, 23 sites showed slight declines in the rate of sea-level rise, and 19 showed slight increases.

A simple, unweighted average of the 42 gauges comes to 2.025 mm/yr average rate of SLR through 2006, or 2.026 mm/yr through 2011 (a difference of one one-thousandth of a millimeter/year), or 1.286 mm/yr if you include Peltier's VM2 GIA adjustments.

The bottom line is that, as measured by the 42 best U.S. long-term trend tide stations, the average rate of sea-level rise over the 5-year period from 2006-2011 is virtually identical to the rate for the full data record (averaging 87.4 years duration) -- more proof that there's been no detectable acceleration in rate of sea-level rise in response to elevated CO2 levels.
March 8, 2013 — updated spreadsheets with latest NOAA and PSMSL data.
March 1, 2013 — Rev 0.6, most of the spreadsheets here now have clickable column headers. Click a column header to sort the data by that column. Click again to reverse the sort order.
September 29, 2012 — Rev. 0.5, added more papers to the Papers page, and more resources to the Resources page
August 23, 2012 — Rev 0.2-0.4, moved resources list to Resources page, and added BlogRoll, Papers & Data pages
August 19, 2012 — Rev 0.1
August 15, 2012 — under construction