diff --git a/.github/workflows/build-docs.yml b/.github/workflows/build-docs.yml
index 76d376d0f..42d1e312e 100644
--- a/.github/workflows/build-docs.yml
+++ b/.github/workflows/build-docs.yml
@@ -16,7 +16,7 @@ jobs:
         os:
         - ubuntu-latest
         python-version:
-        - '3.8'
+        - '3.9'
 
       fail-fast: false
 
diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index 350082375..13c059b57 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -18,7 +18,7 @@ jobs:
         os:
         - ubuntu-latest
         python-version:
-        - '3.8'
+        - '3.9'
 
       fail-fast: false
 
diff --git a/.github/workflows/pytest-dependency.yml b/.github/workflows/pytest-dependency.yml
index 281241e7b..56e5249a8 100644
--- a/.github/workflows/pytest-dependency.yml
+++ b/.github/workflows/pytest-dependency.yml
@@ -28,7 +28,7 @@ jobs:
       run: pip install pandas==1.1.1 numpy==1.19.0 matplotlib==3.5.0 iam-units==2020.4.21 xlrd==2.0 pint==0.13
 
     - name: Install other dependencies and package
-      run: pip install -e .[tests,optional_plotting,optional_io_formats,tutorials]
+      run: pip install .[tests,optional_plotting,optional_io_formats,tutorials]
 
     - name: Test with pytest
       run: pytest tests --mpl
diff --git a/.github/workflows/pytest.yml b/.github/workflows/pytest.yml
index 2c4d5859e..9792125c7 100644
--- a/.github/workflows/pytest.yml
+++ b/.github/workflows/pytest.yml
@@ -18,6 +18,7 @@ jobs:
         - ubuntu-latest
         - windows-latest
         python-version:
+        - '3.10'
         - '3.9'
         - '3.8'
         # Remove dependency `importlib_metadata` when dropping support for Python 3.7
@@ -37,7 +38,7 @@ jobs:
         python-version: ${{ matrix.python-version }}
 
     - name: Install dependencies and package
-      run: pip install -e .[tests,optional_plotting,optional_io_formats,tutorials]
+      run: pip install .[tests,optional_plotting,optional_io_formats,tutorials]
 
     - name: Test with pytest
       if: ${{ matrix.python-version != '3.9' }}
diff --git a/README.md b/README.md
index 24d98b12d..f9007d2da 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ pyam: analysis & visualization <br /> of integrated-assessment and macro-energy
 
 <!-- replace python version by dynamic reference to pypi once Python versions are configured there -->
 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
-[![python](https://img.shields.io/badge/python-3.7_|_3.8_|_3.9-blue?logo=python&logoColor=white)](https://github.com/IAMconsortium/pyam)
+[![python](https://img.shields.io/badge/python-3.7_|_3.8_|_3.9_|_3.10-blue?logo=python&logoColor=white)](https://github.com/IAMconsortium/pyam)
 [![pytest](https://github.com/IAMconsortium/pyam/actions/workflows/pytest.yml/badge.svg)](https://github.com/IAMconsortium/pyam/actions/workflows/pytest.yml)
 [![ReadTheDocs](https://readthedocs.org/projects/pyam-iamc/badge/?version=latest)](https://pyam-iamc.readthedocs.io/en/latest/?badge=latest)
 [![codecov](https://codecov.io/gh/IAMconsortium/pyam/branch/main/graph/badge.svg)](https://codecov.io/gh/IAMconsortium/pyam)
diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index c1f32f442..6d44e163c 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -1,4 +1,10 @@
-# Next Release
+# Release v1.4.0
+
+## Highlights
+
+- Add colors used for IPCC AR6 WGIII scenario analysis
+- Support scenario data with mixed 'year' and 'datetime' domain (beta) 
+- Add explicit support for Python 3.10
 
 ## Dependency changes
 
diff --git a/doc/logos/pyam-header.png b/doc/logos/pyam-header.png
old mode 100644
new mode 100755
index 0dfba42b4..c7b1b83c2
Binary files a/doc/logos/pyam-header.png and b/doc/logos/pyam-header.png differ
diff --git a/doc/logos/pyam-social-media.png b/doc/logos/pyam-social-media.png
old mode 100644
new mode 100755
index d90403ce6..15bef9e2f
Binary files a/doc/logos/pyam-social-media.png and b/doc/logos/pyam-social-media.png differ
diff --git a/doc/source/index.rst b/doc/source/index.rst
index 81d9e4ff2..971769425 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -24,7 +24,7 @@ Release v\ |version|.
 .. |black| image:: https://img.shields.io/badge/code%20style-black-000000.svg
    :target: https://github.com/psf/black
 
-.. |python| image:: https://img.shields.io/badge/python-3.7_|_3.8_|_3.9-blue?logo=python&logoColor=white
+.. |python| image:: https://img.shields.io/badge/python-3.7_|_3.8_|_3.9_|_3.10-blue?logo=python&logoColor=white
    :target: https://github.com/IAMconsortium/pyam
 
 .. |pytest| image:: https://github.com/IAMconsortium/pyam/actions/workflows/pytest.yml/badge.svg
diff --git a/setup.cfg b/setup.cfg
index d43741247..89b106b6a 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -19,6 +19,7 @@ classifiers =
 [options]
 packages = pyam
 include_package_data = True
+python_requires = >=3.7, <3.11
 
 # NOTE TO DEVS
 # If you change a minimum version below, please explicitly implement the change