<p>When I need data about past and future projected land use change, I usually refer to the global dataset that was developed for the global climate simulations CMIP6. 
The dataset is the Land Use Harmonization V.2 <a href="https://luh.umd.edu/" rel="noreferrer">LUHv2</a> and it was developed by researchers at the <a href="https://geog.umd.edu/facultyprofile/hurtt/george" rel="noreferrer">University of Maryland</a>. </p>

<p>Reading the <a href="https://gsweb1vh2.umd.edu/LUH2/LUH2_v2h_README.pdf" rel="noreferrer">supporting document</a> of the dataset, among others, the following characteristics are reported:</p>

<blockquote>
  <ul>
  <li>global domain;</li>
  <li>850­‐2100 annual land-use states, transitions, and gridded mgt layers;</li>
  <li>0.25 x 0.25 degree spatial resolution;</li>
  <li>12 possible land-­use states including separation of Primary and Secondary natural  vegetation into Forest and Non‐forest sub-­types,
  Pasture into Managed Pasture and  Rangeland, and Cropland into
  multiple crop functional types</li>
  </ul>
</blockquote>

<p>The dataset is composed of a set of simulations using different land surface models:</p>

<blockquote>
  <p>These datasets are being developed as a contribution of the Land-Use
  Model Intercomparison Project (<a href="http://www.cesm.ucar.edu/projects/CMIP6/LUMIP/" rel="noreferrer">LUMIP</a>) to the Forcing Group for CMIP6</p>
</blockquote>

<p>Data can be downloaded from <a href="https://luh.umd.edu/data.shtml" rel="noreferrer">this page</a>.</p>

<p>Of course, the layers you find here are "just" models' results, but as much as past observations made a good calibration possible, the variations reported are likely be the most accurate information about the evolution of the world forested areas currently available.</p>

CC BY-SA 4.0
2020-03-03T15:45:48.990Z
Thanks. Looks promising. It has a file from 815 AD to 2015 indicating whether area is forest or not. Looks like the building block to compute what I want. Not sure what format data comes in though.
luchonacho
CC BY-SA 4.0
2020-03-03T20:14:25.583Z
@luchonacho The files are in netCDF (`*.nc` files). It is quite stright-forward to work with them in a Linux environment (similar under MacOS). Might be a bit difficult under Windows. There are [Python](https://unidata.github.io/netcdf4-python/) and [R](https://CRAN.R-project.org/package=ncdf4) netCDF4 packages available. The basic netCDF library offers the binary `ncdump` to print out the header of netCDF files (`ncdump -h FILENAME`). Quick plotting of netCDF content: [ncview](http://meteora.ucsd.edu/~pierce/ncview_home_page.html) or [Panoply](https://www.giss.nasa.gov/tools/panoply/).
daniel.heydebreck
CC BY-SA 4.0
2020-03-04T11:07:22.537Z
@luchonacho, in addition to what Danel righly pointed out, you can also convert netCDF files in raster files using Arcmap (https://desktop.arcgis.com/en/arcmap/10.3/manage-data/netcdf/reading-netcdf-data-as-a-raster-layer.htm). I'm sure also QGIS would have similar functionalities.
Nemesi
CC BY-SA 4.0
2020-03-03T15:17:47.623Z
2020-03-03T15:17:47.623Z
Nemesi
<p>Is there long historical data (at least a few centuries back), at the world level, of forest area? I've only found data by the FAO starting in 1990 (see <a href="http://www.fao.org/state-of-forests/en/" rel="nofollow noreferrer">here</a>). There is some older evidence for a few regions and countries but no aggregate measure (for instance, see <a href="https://ourworldindata.org/forests#changes-in-forest-cover-by-world-region" rel="nofollow noreferrer">here</a>). Any help is appreciated.</p>

CC BY-SA 4.0
2020-03-02T19:43:13.820Z
It is highly improbable that the data you are looking for exists. When I was roaming Borneo in the 1960s, there were substantial areas of the map left blank because they hadn't been mapped. We had to substitute aerial photographs. My information is that the same situation existed and to a lesser extent still exists in other rainforests. There is no possibility of accurate maps or measurements a few centuries back.
Michael Walsby
CC BY-SA 4.0
2020-03-03T09:15:52.343Z
@MichaelWalsby There is some hope — with considerable difficulty it may be possible to estimate historical forest cover.  See https://earthscience.stackexchange.com/q/5262/6.  However, it would be a huge effort to establish such a record on a global basis, so I agree that such a dataset probably doesn't exist with any level of accuracy and precision.
gerrit
CC BY-SA 4.0
2020-03-03T12:47:45.047Z
@MichaelWalsby [Economists](http://www.ggdc.net/maddison/oriindex.htm) have (with a debatable degree of accuracy, for sure), computed GDP for the world since 1AD. That's a way more difficult task imo. You mention Borneo. Well, based on some recent information, surely something can be deduced. I mean, if there is a rainforest now, there must have been 100 years ago, and perhaps 500 years ago. We are not talking about exact metrics here. Even a rough estimate would be useful.
luchonacho
CC BY-SA 4.0
2020-03-03T13:04:25.973Z
@luchonacho It would be useful if you added the spatial resolution that you're interested in, e.g., country level, 1 degree, 100 metres.  As the other comments mention, some things will be more feasible than others.
Deditos
CC BY-SA 4.0
2020-03-04T11:45:29.020Z
A lot of British forest, mainly oak, was cut down to build England's famous 'wooden walls', but I doubt that there are any accurate records of the clearance..
Michael Walsby
CC BY-SA 4.0
2020-03-04T20:13:28.857Z
Depending on what you're planning to use the data for, you might want to consider that there's a difference between forest COVER and forest MASS.  For instance, it's claimed that the northeastern US has more forest cover now that it did a century or so ago, but much of that cover is small, spindly scrub rather than old-growth.
jamesqf
<forest><database>
Historical data on world's forest area
luchonacho
# Historical data on world's forest area

(Asked by: username_0 on 2020-03-02)

Is there long historical data (at least a few centuries back), at the world level, of forest area? I've only found data by the FAO starting in 1990 (see [here](http://www.fao.org/state-of-forests/en/)). There is some older evidence for a few regions and countries but no aggregate measure (for instance, see [here](https://ourworldindata.org/forests#changes-in-forest-cover-by-world-region)). Any help is appreciated.

**Tags:** forest, database

> **Comments:**
> **username_1**: It is highly improbable that the data you are looking for exists. When I was roaming Borneo in the 1960s, there were substantial areas of the map left blank because they hadn't been mapped. We had to substitute aerial photographs. My information is that the same situation existed and to a lesser extent still exists in other rainforests. There is no possibility of accurate maps or measurements a few centuries back.  
> **username_2**: @username_1 There is some hope — with considerable difficulty it may be possible to estimate historical forest cover.  See https://earthscience.stackexchange.com/q/5262/6.  However, it would be a huge effort to establish such a record on a global basis, so I agree that such a dataset probably doesn't exist with any level of accuracy and precision.  
> **username_0**: @username_1 [Economists](http://www.ggdc.net/maddison/oriindex.htm) have (with a debatable degree of accuracy, for sure), computed GDP for the world since 1AD. That's a way more difficult task imo. You mention Borneo. Well, based on some recent information, surely something can be deduced. I mean, if there is a rainforest now, there must have been 100 years ago, and perhaps 500 years ago. We are not talking about exact metrics here. Even a rough estimate would be useful.  
> **username_3**: @username_0 It would be useful if you added the spatial resolution that you're interested in, e.g., country level, 1 degree, 100 metres.  As the other comments mention, some things will be more feasible than others.  
> **username_1**: A lot of British forest, mainly oak, was cut down to build England's famous 'wooden walls', but I doubt that there are any accurate records of the clearance..  
> **username_4**: Depending on what you're planning to use the data for, you might want to consider that there's a difference between forest COVER and forest MASS.  For instance, it's claimed that the northeastern US has more forest cover now that it did a century or so ago, but much of that cover is small, spindly scrub rather than old-growth.  

---

## 1 answers

### Answer by username_5 on 2020-03-03. Score: 6

When I need data about past and future projected land use change, I usually refer to the global dataset that was developed for the global climate simulations CMIP6.
The dataset is the Land Use Harmonization V.2 [LUHv2](https://luh.umd.edu/) and it was developed by researchers at the [University of Maryland](https://geog.umd.edu/facultyprofile/hurtt/george).

Reading the [supporting document](https://gsweb1vh2.umd.edu/LUH2/LUH2_v2h_README.pdf) of the dataset, among others, the following characteristics are reported:

> * global domain;
> * 850­‐2100 annual land-use states, transitions, and gridded mgt layers;
> * 0.25 x 0.25 degree spatial resolution;
> * 12 possible land-­use states including separation of Primary and Secondary natural vegetation into Forest and Non‐forest sub-­types,
>   Pasture into Managed Pasture and Rangeland, and Cropland into
>   multiple crop functional types

The dataset is composed of a set of simulations using different land surface models:

> These datasets are being developed as a contribution of the Land-Use
> Model Intercomparison Project ([LUMIP](http://www.cesm.ucar.edu/projects/CMIP6/LUMIP/)) to the Forcing Group for CMIP6

Data can be downloaded from [this page](https://luh.umd.edu/data.shtml).

Of course, the layers you find here are "just" models' results, but as much as past observations made a good calibration possible, the variations reported are likely be the most accurate information about the evolution of the world forested areas currently available.

> **Comments:**
> **username_0**: Thanks. Looks promising. It has a file from 815 AD to 2015 indicating whether area is forest or not. Looks like the building block to compute what I want. Not sure what format data comes in though.  
> **username_6**: @username_0 The files are in netCDF (`*.nc` files). It is quite stright-forward to work with them in a Linux environment (similar under MacOS). Might be a bit difficult under Windows. There are [Python](https://unidata.github.io/netcdf4-python/) and [R](https://CRAN.R-project.org/package=ncdf4) netCDF4 packages available. The basic netCDF library offers the binary `ncdump` to print out the header of netCDF files (`ncdump -h FILENAME`). Quick plotting of netCDF content: [ncview](http://meteora.ucsd.edu/~pierce/ncview_home_page.html) or [Panoply](https://www.giss.nasa.gov/tools/panoply/).  
> **username_5**: @username_0, in addition to what Danel righly pointed out, you can also convert netCDF files in raster files using Arcmap (https://desktop.arcgis.com/en/arcmap/10.3/manage-data/netcdf/reading-netcdf-data-as-a-raster-layer.htm). I'm sure also QGIS would have similar functionalities.  

---

